From 918bc4b74f2f9af49d1c3efa8846d392e1ee324e Mon Sep 17 00:00:00 2001
From: Jonathan Swoboda <154711427+swoboda1337@users.noreply.github.com>
Date: Mon, 22 Dec 2025 15:41:14 -0500
Subject: [PATCH 1/5] [esp32] Remove remaining using_esp_idf checks (#12623)

Co-authored-by: Claude <noreply@anthropic.com>
---
 esphome/components/captive_portal/__init__.py |  2 +-
 esphome/components/i2c/__init__.py            |  2 +-
 esphome/components/i2s_audio/__init__.py      |  5 +++--
 esphome/components/improv_serial/__init__.py  |  2 +-
 esphome/components/mdns/__init__.py           |  6 ++----
 esphome/components/network/__init__.py        | 10 +++++-----
 esphome/components/wifi/__init__.py           |  4 ++--
 esphome/core/__init__.py                      |  5 +++++
 8 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/esphome/components/captive_portal/__init__.py b/esphome/components/captive_portal/__init__.py
index 25d0a22083..763e2e4ec5 100644
--- a/esphome/components/captive_portal/__init__.py
+++ b/esphome/components/captive_portal/__init__.py
@@ -25,7 +25,7 @@ _LOGGER = logging.getLogger(__name__)
 
 def AUTO_LOAD() -> list[str]:
     auto_load = ["web_server_base", "ota.web_server"]
-    if CORE.using_esp_idf:
+    if CORE.is_esp32:
         auto_load.append("socket")
     return auto_load
 
diff --git a/esphome/components/i2c/__init__.py b/esphome/components/i2c/__init__.py
index b7436ccc39..56e0c8e4ab 100644
--- a/esphome/components/i2c/__init__.py
+++ b/esphome/components/i2c/__init__.py
@@ -146,7 +146,7 @@ def _final_validate(config):
     full_config = fv.full_config.get()[CONF_I2C]
     if CORE.using_zephyr and len(full_config) > 1:
         raise cv.Invalid("Second i2c is not implemented on Zephyr yet")
-    if CORE.using_esp_idf and get_esp32_variant() in ESP32_I2C_CAPABILITIES:
+    if CORE.is_esp32 and get_esp32_variant() in ESP32_I2C_CAPABILITIES:
         variant = get_esp32_variant()
         max_num = ESP32_I2C_CAPABILITIES[variant]["NUM"]
         if len(full_config) > max_num:
diff --git a/esphome/components/i2s_audio/__init__.py b/esphome/components/i2s_audio/__init__.py
index 61c5ca4ec1..d3128c5f4c 100644
--- a/esphome/components/i2s_audio/__init__.py
+++ b/esphome/components/i2s_audio/__init__.py
@@ -232,6 +232,8 @@ def validate_use_legacy(value):
         if (not value[CONF_USE_LEGACY]) and (CORE.using_arduino):
             raise cv.Invalid("Arduino supports only the legacy i2s driver")
         _set_use_legacy_driver(value[CONF_USE_LEGACY])
+    elif CORE.using_arduino:
+        _set_use_legacy_driver(True)
     return value
 
 
@@ -261,8 +263,7 @@ def _final_validate(_):
 
 
 def use_legacy():
-    legacy_driver = _get_use_legacy_driver()
-    return not (CORE.using_esp_idf and not legacy_driver)
+    return _get_use_legacy_driver()
 
 
 FINAL_VALIDATE_SCHEMA = _final_validate
diff --git a/esphome/components/improv_serial/__init__.py b/esphome/components/improv_serial/__init__.py
index 7f88b17e11..9a2ac2f40f 100644
--- a/esphome/components/improv_serial/__init__.py
+++ b/esphome/components/improv_serial/__init__.py
@@ -26,7 +26,7 @@ def validate_logger(config):
     logger_conf = fv.full_config.get()[CONF_LOGGER]
     if logger_conf[CONF_BAUD_RATE] == 0:
         raise cv.Invalid("improv_serial requires the logger baud_rate to be not 0")
-    if CORE.using_esp_idf and (
+    if CORE.is_esp32 and (
         logger_conf[CONF_HARDWARE_UART] == USB_CDC
         and get_esp32_variant() == VARIANT_ESP32S3
     ):
diff --git a/esphome/components/mdns/__init__.py b/esphome/components/mdns/__init__.py
index 99b728b249..3088d8ad7e 100644
--- a/esphome/components/mdns/__init__.py
+++ b/esphome/components/mdns/__init__.py
@@ -157,14 +157,12 @@ async def to_code(config):
         return
 
     if CORE.using_arduino:
-        if CORE.is_esp32:
-            cg.add_library("ESPmDNS", None)
-        elif CORE.is_esp8266:
+        if CORE.is_esp8266:
             cg.add_library("ESP8266mDNS", None)
         elif CORE.is_rp2040:
             cg.add_library("LEAmDNS", None)
 
-    if CORE.using_esp_idf:
+    if CORE.is_esp32:
         add_idf_component(name="espressif/mdns", ref="1.9.1")
 
     cg.add_define("USE_MDNS")
diff --git a/esphome/components/network/__init__.py b/esphome/components/network/__init__.py
index d7a51fb0c6..5b63bbfce9 100644
--- a/esphome/components/network/__init__.py
+++ b/esphome/components/network/__init__.py
@@ -156,7 +156,7 @@ async def to_code(config):
             "High performance networking disabled by user configuration (overriding component request)"
         )
 
-    if CORE.is_esp32 and CORE.using_esp_idf and should_enable:
+    if CORE.is_esp32 and should_enable:
         # Check if PSRAM is guaranteed (set by psram component during final validation)
         psram_guaranteed = psram_is_guaranteed()
 
@@ -210,12 +210,12 @@ async def to_code(config):
                 "USE_NETWORK_MIN_IPV6_ADDR_COUNT", config[CONF_MIN_IPV6_ADDR_COUNT]
             )
         if CORE.is_esp32:
-            if CORE.using_esp_idf:
-                add_idf_sdkconfig_option("CONFIG_LWIP_IPV6", enable_ipv6)
-                add_idf_sdkconfig_option("CONFIG_LWIP_IPV6_AUTOCONFIG", enable_ipv6)
-            else:
+            if CORE.using_arduino:
                 add_idf_sdkconfig_option("CONFIG_LWIP_IPV6", True)
                 add_idf_sdkconfig_option("CONFIG_LWIP_IPV6_AUTOCONFIG", True)
+            else:
+                add_idf_sdkconfig_option("CONFIG_LWIP_IPV6", enable_ipv6)
+                add_idf_sdkconfig_option("CONFIG_LWIP_IPV6_AUTOCONFIG", enable_ipv6)
         elif enable_ipv6:
             cg.add_build_flag("-DCONFIG_LWIP_IPV6")
             cg.add_build_flag("-DCONFIG_LWIP_IPV6_AUTOCONFIG")
diff --git a/esphome/components/wifi/__init__.py b/esphome/components/wifi/__init__.py
index fb23837e78..232e8d4f27 100644
--- a/esphome/components/wifi/__init__.py
+++ b/esphome/components/wifi/__init__.py
@@ -464,7 +464,7 @@ async def to_code(config):
         )
         cg.add(var.set_ap_timeout(conf[CONF_AP_TIMEOUT]))
         cg.add_define("USE_WIFI_AP")
-    elif CORE.is_esp32 and CORE.using_esp_idf:
+    elif CORE.is_esp32 and not CORE.using_arduino:
         add_idf_sdkconfig_option("CONFIG_ESP_WIFI_SOFTAP_SUPPORT", False)
         add_idf_sdkconfig_option("CONFIG_LWIP_DHCPS", False)
 
@@ -509,7 +509,7 @@ async def to_code(config):
         add_idf_sdkconfig_option("CONFIG_SPIRAM_TRY_ALLOCATE_WIFI_LWIP", True)
 
     # Apply high performance WiFi settings if high performance networking is enabled
-    if CORE.is_esp32 and CORE.using_esp_idf and has_high_performance_networking():
+    if CORE.is_esp32 and has_high_performance_networking():
         # Check if PSRAM is guaranteed (set by psram component during final validation)
         psram_guaranteed = psram_is_guaranteed()
 
diff --git a/esphome/core/__init__.py b/esphome/core/__init__.py
index ad9844a3bf..3baec93186 100644
--- a/esphome/core/__init__.py
+++ b/esphome/core/__init__.py
@@ -798,6 +798,11 @@ class EsphomeCore:
 
     @property
     def using_esp_idf(self):
+        _LOGGER.warning(
+            "CORE.using_esp_idf was deprecated in 2026.1, will change behavior in 2026.6. "
+            "ESP32 Arduino builds on top of ESP-IDF, so ESP-IDF features are available in both frameworks. "
+            "Use CORE.is_esp32 and/or CORE.using_arduino instead."
+        )
         return self.target_framework == "esp-idf"
 
     @property

From c8b531ac06d569197da9b6740dd7062f1a7e77d9 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Mon, 22 Dec 2025 11:13:51 -1000
Subject: [PATCH 2/5] [safe_mode] Defer preference sync in clean_rtc to avoid
 blocking event loop (#12625)

---
 esphome/components/safe_mode/safe_mode.cpp | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/esphome/components/safe_mode/safe_mode.cpp b/esphome/components/safe_mode/safe_mode.cpp
index f8e5d7d8e5..c933222273 100644
--- a/esphome/components/safe_mode/safe_mode.cpp
+++ b/esphome/components/safe_mode/safe_mode.cpp
@@ -141,7 +141,14 @@ uint32_t SafeModeComponent::read_rtc_() {
   return val;
 }
 
-void SafeModeComponent::clean_rtc() { this->write_rtc_(0); }
+void SafeModeComponent::clean_rtc() {
+  // Save without sync - preferences will be written at shutdown or by IntervalSyncer.
+  // This avoids blocking the loop for 50+ ms on flash write. If the device crashes
+  // before sync, the boot wasn't really successful anyway and the counter should
+  // remain incremented.
+  uint32_t val = 0;
+  this->rtc_.save(&val);
+}
 
 void SafeModeComponent::on_safe_shutdown() {
   if (this->read_rtc_() != SafeModeComponent::ENTER_SAFE_MODE_MAGIC)

From bdbe72b7f15e0f0dc861546565798dfa9ed86fa9 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Mon, 22 Dec 2025 11:14:11 -1000
Subject: [PATCH 3/5] [web_server] Make internal JSON helper methods private
 (#12624)

---
 esphome/components/web_server/web_server.cpp | 182 +++++++++----------
 esphome/components/web_server/web_server.h   | 105 ++++++-----
 2 files changed, 154 insertions(+), 133 deletions(-)

diff --git a/esphome/components/web_server/web_server.cpp b/esphome/components/web_server/web_server.cpp
index 207eafad5c..ece9d65121 100644
--- a/esphome/components/web_server/web_server.cpp
+++ b/esphome/components/web_server/web_server.cpp
@@ -455,7 +455,7 @@ void WebServer::handle_sensor_request(AsyncWebServerRequest *request, const UrlM
     // Note: request->method() is always HTTP_GET here (canHandle ensures this)
     if (match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->sensor_json(obj, obj->state, detail);
+      std::string data = this->sensor_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -463,12 +463,12 @@ void WebServer::handle_sensor_request(AsyncWebServerRequest *request, const UrlM
   request->send(404);
 }
 std::string WebServer::sensor_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->sensor_json((sensor::Sensor *) (source), ((sensor::Sensor *) (source))->state, DETAIL_STATE);
+  return web_server->sensor_json_((sensor::Sensor *) (source), ((sensor::Sensor *) (source))->state, DETAIL_STATE);
 }
 std::string WebServer::sensor_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->sensor_json((sensor::Sensor *) (source), ((sensor::Sensor *) (source))->state, DETAIL_ALL);
+  return web_server->sensor_json_((sensor::Sensor *) (source), ((sensor::Sensor *) (source))->state, DETAIL_ALL);
 }
-std::string WebServer::sensor_json(sensor::Sensor *obj, float value, JsonDetail start_config) {
+std::string WebServer::sensor_json_(sensor::Sensor *obj, float value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -500,7 +500,7 @@ void WebServer::handle_text_sensor_request(AsyncWebServerRequest *request, const
     // Note: request->method() is always HTTP_GET here (canHandle ensures this)
     if (match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->text_sensor_json(obj, obj->state, detail);
+      std::string data = this->text_sensor_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -508,15 +508,15 @@ void WebServer::handle_text_sensor_request(AsyncWebServerRequest *request, const
   request->send(404);
 }
 std::string WebServer::text_sensor_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->text_sensor_json((text_sensor::TextSensor *) (source),
-                                      ((text_sensor::TextSensor *) (source))->state, DETAIL_STATE);
+  return web_server->text_sensor_json_((text_sensor::TextSensor *) (source),
+                                       ((text_sensor::TextSensor *) (source))->state, DETAIL_STATE);
 }
 std::string WebServer::text_sensor_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->text_sensor_json((text_sensor::TextSensor *) (source),
-                                      ((text_sensor::TextSensor *) (source))->state, DETAIL_ALL);
+  return web_server->text_sensor_json_((text_sensor::TextSensor *) (source),
+                                       ((text_sensor::TextSensor *) (source))->state, DETAIL_ALL);
 }
-std::string WebServer::text_sensor_json(text_sensor::TextSensor *obj, const std::string &value,
-                                        JsonDetail start_config) {
+std::string WebServer::text_sensor_json_(text_sensor::TextSensor *obj, const std::string &value,
+                                         JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -542,7 +542,7 @@ void WebServer::handle_switch_request(AsyncWebServerRequest *request, const UrlM
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->switch_json(obj, obj->state, detail);
+      std::string data = this->switch_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -584,12 +584,12 @@ void WebServer::handle_switch_request(AsyncWebServerRequest *request, const UrlM
   request->send(404);
 }
 std::string WebServer::switch_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->switch_json((switch_::Switch *) (source), ((switch_::Switch *) (source))->state, DETAIL_STATE);
+  return web_server->switch_json_((switch_::Switch *) (source), ((switch_::Switch *) (source))->state, DETAIL_STATE);
 }
 std::string WebServer::switch_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->switch_json((switch_::Switch *) (source), ((switch_::Switch *) (source))->state, DETAIL_ALL);
+  return web_server->switch_json_((switch_::Switch *) (source), ((switch_::Switch *) (source))->state, DETAIL_ALL);
 }
-std::string WebServer::switch_json(switch_::Switch *obj, bool value, JsonDetail start_config) {
+std::string WebServer::switch_json_(switch_::Switch *obj, bool value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -610,7 +610,7 @@ void WebServer::handle_button_request(AsyncWebServerRequest *request, const UrlM
       continue;
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->button_json(obj, detail);
+      std::string data = this->button_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
     } else if (match.method_equals("press")) {
       this->defer([obj]() { obj->press(); });
@@ -624,12 +624,12 @@ void WebServer::handle_button_request(AsyncWebServerRequest *request, const UrlM
   request->send(404);
 }
 std::string WebServer::button_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->button_json((button::Button *) (source), DETAIL_STATE);
+  return web_server->button_json_((button::Button *) (source), DETAIL_STATE);
 }
 std::string WebServer::button_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->button_json((button::Button *) (source), DETAIL_ALL);
+  return web_server->button_json_((button::Button *) (source), DETAIL_ALL);
 }
-std::string WebServer::button_json(button::Button *obj, JsonDetail start_config) {
+std::string WebServer::button_json_(button::Button *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -655,7 +655,7 @@ void WebServer::handle_binary_sensor_request(AsyncWebServerRequest *request, con
     // Note: request->method() is always HTTP_GET here (canHandle ensures this)
     if (match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->binary_sensor_json(obj, obj->state, detail);
+      std::string data = this->binary_sensor_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -663,14 +663,14 @@ void WebServer::handle_binary_sensor_request(AsyncWebServerRequest *request, con
   request->send(404);
 }
 std::string WebServer::binary_sensor_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->binary_sensor_json((binary_sensor::BinarySensor *) (source),
-                                        ((binary_sensor::BinarySensor *) (source))->state, DETAIL_STATE);
+  return web_server->binary_sensor_json_((binary_sensor::BinarySensor *) (source),
+                                         ((binary_sensor::BinarySensor *) (source))->state, DETAIL_STATE);
 }
 std::string WebServer::binary_sensor_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->binary_sensor_json((binary_sensor::BinarySensor *) (source),
-                                        ((binary_sensor::BinarySensor *) (source))->state, DETAIL_ALL);
+  return web_server->binary_sensor_json_((binary_sensor::BinarySensor *) (source),
+                                         ((binary_sensor::BinarySensor *) (source))->state, DETAIL_ALL);
 }
-std::string WebServer::binary_sensor_json(binary_sensor::BinarySensor *obj, bool value, JsonDetail start_config) {
+std::string WebServer::binary_sensor_json_(binary_sensor::BinarySensor *obj, bool value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -696,7 +696,7 @@ void WebServer::handle_fan_request(AsyncWebServerRequest *request, const UrlMatc
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->fan_json(obj, detail);
+      std::string data = this->fan_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
     } else if (match.method_equals("toggle")) {
       this->defer([obj]() { obj->toggle().perform(); });
@@ -738,12 +738,12 @@ void WebServer::handle_fan_request(AsyncWebServerRequest *request, const UrlMatc
   request->send(404);
 }
 std::string WebServer::fan_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->fan_json((fan::Fan *) (source), DETAIL_STATE);
+  return web_server->fan_json_((fan::Fan *) (source), DETAIL_STATE);
 }
 std::string WebServer::fan_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->fan_json((fan::Fan *) (source), DETAIL_ALL);
+  return web_server->fan_json_((fan::Fan *) (source), DETAIL_ALL);
 }
-std::string WebServer::fan_json(fan::Fan *obj, JsonDetail start_config) {
+std::string WebServer::fan_json_(fan::Fan *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -776,7 +776,7 @@ void WebServer::handle_light_request(AsyncWebServerRequest *request, const UrlMa
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->light_json(obj, detail);
+      std::string data = this->light_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
     } else if (match.method_equals("toggle")) {
       this->defer([obj]() { obj->toggle().perform(); });
@@ -816,12 +816,12 @@ void WebServer::handle_light_request(AsyncWebServerRequest *request, const UrlMa
   request->send(404);
 }
 std::string WebServer::light_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->light_json((light::LightState *) (source), DETAIL_STATE);
+  return web_server->light_json_((light::LightState *) (source), DETAIL_STATE);
 }
 std::string WebServer::light_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->light_json((light::LightState *) (source), DETAIL_ALL);
+  return web_server->light_json_((light::LightState *) (source), DETAIL_ALL);
 }
-std::string WebServer::light_json(light::LightState *obj, JsonDetail start_config) {
+std::string WebServer::light_json_(light::LightState *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -854,7 +854,7 @@ void WebServer::handle_cover_request(AsyncWebServerRequest *request, const UrlMa
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->cover_json(obj, detail);
+      std::string data = this->cover_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -903,12 +903,12 @@ void WebServer::handle_cover_request(AsyncWebServerRequest *request, const UrlMa
   request->send(404);
 }
 std::string WebServer::cover_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->cover_json((cover::Cover *) (source), DETAIL_STATE);
+  return web_server->cover_json_((cover::Cover *) (source), DETAIL_STATE);
 }
 std::string WebServer::cover_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->cover_json((cover::Cover *) (source), DETAIL_ALL);
+  return web_server->cover_json_((cover::Cover *) (source), DETAIL_ALL);
 }
-std::string WebServer::cover_json(cover::Cover *obj, JsonDetail start_config) {
+std::string WebServer::cover_json_(cover::Cover *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -942,7 +942,7 @@ void WebServer::handle_number_request(AsyncWebServerRequest *request, const UrlM
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->number_json(obj, obj->state, detail);
+      std::string data = this->number_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -962,12 +962,12 @@ void WebServer::handle_number_request(AsyncWebServerRequest *request, const UrlM
 }
 
 std::string WebServer::number_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->number_json((number::Number *) (source), ((number::Number *) (source))->state, DETAIL_STATE);
+  return web_server->number_json_((number::Number *) (source), ((number::Number *) (source))->state, DETAIL_STATE);
 }
 std::string WebServer::number_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->number_json((number::Number *) (source), ((number::Number *) (source))->state, DETAIL_ALL);
+  return web_server->number_json_((number::Number *) (source), ((number::Number *) (source))->state, DETAIL_ALL);
 }
-std::string WebServer::number_json(number::Number *obj, float value, JsonDetail start_config) {
+std::string WebServer::number_json_(number::Number *obj, float value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1009,7 +1009,7 @@ void WebServer::handle_date_request(AsyncWebServerRequest *request, const UrlMat
       continue;
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->date_json(obj, detail);
+      std::string data = this->date_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1035,12 +1035,12 @@ void WebServer::handle_date_request(AsyncWebServerRequest *request, const UrlMat
 }
 
 std::string WebServer::date_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->date_json((datetime::DateEntity *) (source), DETAIL_STATE);
+  return web_server->date_json_((datetime::DateEntity *) (source), DETAIL_STATE);
 }
 std::string WebServer::date_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->date_json((datetime::DateEntity *) (source), DETAIL_ALL);
+  return web_server->date_json_((datetime::DateEntity *) (source), DETAIL_ALL);
 }
-std::string WebServer::date_json(datetime::DateEntity *obj, JsonDetail start_config) {
+std::string WebServer::date_json_(datetime::DateEntity *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1072,7 +1072,7 @@ void WebServer::handle_time_request(AsyncWebServerRequest *request, const UrlMat
       continue;
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->time_json(obj, detail);
+      std::string data = this->time_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1097,12 +1097,12 @@ void WebServer::handle_time_request(AsyncWebServerRequest *request, const UrlMat
   request->send(404);
 }
 std::string WebServer::time_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->time_json((datetime::TimeEntity *) (source), DETAIL_STATE);
+  return web_server->time_json_((datetime::TimeEntity *) (source), DETAIL_STATE);
 }
 std::string WebServer::time_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->time_json((datetime::TimeEntity *) (source), DETAIL_ALL);
+  return web_server->time_json_((datetime::TimeEntity *) (source), DETAIL_ALL);
 }
-std::string WebServer::time_json(datetime::TimeEntity *obj, JsonDetail start_config) {
+std::string WebServer::time_json_(datetime::TimeEntity *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1134,7 +1134,7 @@ void WebServer::handle_datetime_request(AsyncWebServerRequest *request, const Ur
       continue;
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->datetime_json(obj, detail);
+      std::string data = this->datetime_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1159,12 +1159,12 @@ void WebServer::handle_datetime_request(AsyncWebServerRequest *request, const Ur
   request->send(404);
 }
 std::string WebServer::datetime_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->datetime_json((datetime::DateTimeEntity *) (source), DETAIL_STATE);
+  return web_server->datetime_json_((datetime::DateTimeEntity *) (source), DETAIL_STATE);
 }
 std::string WebServer::datetime_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->datetime_json((datetime::DateTimeEntity *) (source), DETAIL_ALL);
+  return web_server->datetime_json_((datetime::DateTimeEntity *) (source), DETAIL_ALL);
 }
-std::string WebServer::datetime_json(datetime::DateTimeEntity *obj, JsonDetail start_config) {
+std::string WebServer::datetime_json_(datetime::DateTimeEntity *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1199,7 +1199,7 @@ void WebServer::handle_text_request(AsyncWebServerRequest *request, const UrlMat
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->text_json(obj, obj->state, detail);
+      std::string data = this->text_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1219,12 +1219,12 @@ void WebServer::handle_text_request(AsyncWebServerRequest *request, const UrlMat
 }
 
 std::string WebServer::text_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->text_json((text::Text *) (source), ((text::Text *) (source))->state, DETAIL_STATE);
+  return web_server->text_json_((text::Text *) (source), ((text::Text *) (source))->state, DETAIL_STATE);
 }
 std::string WebServer::text_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->text_json((text::Text *) (source), ((text::Text *) (source))->state, DETAIL_ALL);
+  return web_server->text_json_((text::Text *) (source), ((text::Text *) (source))->state, DETAIL_ALL);
 }
-std::string WebServer::text_json(text::Text *obj, const std::string &value, JsonDetail start_config) {
+std::string WebServer::text_json_(text::Text *obj, const std::string &value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1255,7 +1255,7 @@ void WebServer::handle_select_request(AsyncWebServerRequest *request, const UrlM
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->select_json(obj, obj->has_state() ? obj->current_option() : "", detail);
+      std::string data = this->select_json_(obj, obj->has_state() ? obj->current_option() : "", detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1276,13 +1276,13 @@ void WebServer::handle_select_request(AsyncWebServerRequest *request, const UrlM
 }
 std::string WebServer::select_state_json_generator(WebServer *web_server, void *source) {
   auto *obj = (select::Select *) (source);
-  return web_server->select_json(obj, obj->has_state() ? obj->current_option() : "", DETAIL_STATE);
+  return web_server->select_json_(obj, obj->has_state() ? obj->current_option() : "", DETAIL_STATE);
 }
 std::string WebServer::select_all_json_generator(WebServer *web_server, void *source) {
   auto *obj = (select::Select *) (source);
-  return web_server->select_json(obj, obj->has_state() ? obj->current_option() : "", DETAIL_ALL);
+  return web_server->select_json_(obj, obj->has_state() ? obj->current_option() : "", DETAIL_ALL);
 }
-std::string WebServer::select_json(select::Select *obj, const char *value, JsonDetail start_config) {
+std::string WebServer::select_json_(select::Select *obj, const char *value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1312,7 +1312,7 @@ void WebServer::handle_climate_request(AsyncWebServerRequest *request, const Url
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->climate_json(obj, detail);
+      std::string data = this->climate_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1342,13 +1342,13 @@ void WebServer::handle_climate_request(AsyncWebServerRequest *request, const Url
 }
 std::string WebServer::climate_state_json_generator(WebServer *web_server, void *source) {
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-  return web_server->climate_json((climate::Climate *) (source), DETAIL_STATE);
+  return web_server->climate_json_((climate::Climate *) (source), DETAIL_STATE);
 }
 std::string WebServer::climate_all_json_generator(WebServer *web_server, void *source) {
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-  return web_server->climate_json((climate::Climate *) (source), DETAIL_ALL);
+  return web_server->climate_json_((climate::Climate *) (source), DETAIL_ALL);
 }
-std::string WebServer::climate_json(climate::Climate *obj, JsonDetail start_config) {
+std::string WebServer::climate_json_(climate::Climate *obj, JsonDetail start_config) {
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   json::JsonBuilder builder;
   JsonObject root = builder.root();
@@ -1456,7 +1456,7 @@ void WebServer::handle_lock_request(AsyncWebServerRequest *request, const UrlMat
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->lock_json(obj, obj->state, detail);
+      std::string data = this->lock_json_(obj, obj->state, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1498,12 +1498,12 @@ void WebServer::handle_lock_request(AsyncWebServerRequest *request, const UrlMat
   request->send(404);
 }
 std::string WebServer::lock_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->lock_json((lock::Lock *) (source), ((lock::Lock *) (source))->state, DETAIL_STATE);
+  return web_server->lock_json_((lock::Lock *) (source), ((lock::Lock *) (source))->state, DETAIL_STATE);
 }
 std::string WebServer::lock_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->lock_json((lock::Lock *) (source), ((lock::Lock *) (source))->state, DETAIL_ALL);
+  return web_server->lock_json_((lock::Lock *) (source), ((lock::Lock *) (source))->state, DETAIL_ALL);
 }
-std::string WebServer::lock_json(lock::Lock *obj, lock::LockState value, JsonDetail start_config) {
+std::string WebServer::lock_json_(lock::Lock *obj, lock::LockState value, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1530,7 +1530,7 @@ void WebServer::handle_valve_request(AsyncWebServerRequest *request, const UrlMa
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->valve_json(obj, detail);
+      std::string data = this->valve_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1577,12 +1577,12 @@ void WebServer::handle_valve_request(AsyncWebServerRequest *request, const UrlMa
   request->send(404);
 }
 std::string WebServer::valve_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->valve_json((valve::Valve *) (source), DETAIL_STATE);
+  return web_server->valve_json_((valve::Valve *) (source), DETAIL_STATE);
 }
 std::string WebServer::valve_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->valve_json((valve::Valve *) (source), DETAIL_ALL);
+  return web_server->valve_json_((valve::Valve *) (source), DETAIL_ALL);
 }
-std::string WebServer::valve_json(valve::Valve *obj, JsonDetail start_config) {
+std::string WebServer::valve_json_(valve::Valve *obj, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1614,7 +1614,7 @@ void WebServer::handle_alarm_control_panel_request(AsyncWebServerRequest *reques
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->alarm_control_panel_json(obj, obj->get_state(), detail);
+      std::string data = this->alarm_control_panel_json_(obj, obj->get_state(), detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1655,18 +1655,18 @@ void WebServer::handle_alarm_control_panel_request(AsyncWebServerRequest *reques
   request->send(404);
 }
 std::string WebServer::alarm_control_panel_state_json_generator(WebServer *web_server, void *source) {
-  return web_server->alarm_control_panel_json((alarm_control_panel::AlarmControlPanel *) (source),
-                                              ((alarm_control_panel::AlarmControlPanel *) (source))->get_state(),
-                                              DETAIL_STATE);
+  return web_server->alarm_control_panel_json_((alarm_control_panel::AlarmControlPanel *) (source),
+                                               ((alarm_control_panel::AlarmControlPanel *) (source))->get_state(),
+                                               DETAIL_STATE);
 }
 std::string WebServer::alarm_control_panel_all_json_generator(WebServer *web_server, void *source) {
-  return web_server->alarm_control_panel_json((alarm_control_panel::AlarmControlPanel *) (source),
-                                              ((alarm_control_panel::AlarmControlPanel *) (source))->get_state(),
-                                              DETAIL_ALL);
+  return web_server->alarm_control_panel_json_((alarm_control_panel::AlarmControlPanel *) (source),
+                                               ((alarm_control_panel::AlarmControlPanel *) (source))->get_state(),
+                                               DETAIL_ALL);
 }
-std::string WebServer::alarm_control_panel_json(alarm_control_panel::AlarmControlPanel *obj,
-                                                alarm_control_panel::AlarmControlPanelState value,
-                                                JsonDetail start_config) {
+std::string WebServer::alarm_control_panel_json_(alarm_control_panel::AlarmControlPanel *obj,
+                                                 alarm_control_panel::AlarmControlPanelState value,
+                                                 JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1696,7 +1696,7 @@ void WebServer::handle_event_request(AsyncWebServerRequest *request, const UrlMa
     // Note: request->method() is always HTTP_GET here (canHandle ensures this)
     if (match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->event_json(obj, "", detail);
+      std::string data = this->event_json_(obj, "", detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1711,14 +1711,14 @@ static std::string get_event_type(event::Event *event) {
 
 std::string WebServer::event_state_json_generator(WebServer *web_server, void *source) {
   auto *event = static_cast<event::Event *>(source);
-  return web_server->event_json(event, get_event_type(event), DETAIL_STATE);
+  return web_server->event_json_(event, get_event_type(event), DETAIL_STATE);
 }
 // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
 std::string WebServer::event_all_json_generator(WebServer *web_server, void *source) {
   auto *event = static_cast<event::Event *>(source);
-  return web_server->event_json(event, get_event_type(event), DETAIL_ALL);
+  return web_server->event_json_(event, get_event_type(event), DETAIL_ALL);
 }
-std::string WebServer::event_json(event::Event *obj, const std::string &event_type, JsonDetail start_config) {
+std::string WebServer::event_json_(event::Event *obj, const std::string &event_type, JsonDetail start_config) {
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
@@ -1764,7 +1764,7 @@ void WebServer::handle_update_request(AsyncWebServerRequest *request, const UrlM
 
     if (request->method() == HTTP_GET && match.method_empty()) {
       auto detail = get_request_detail(request);
-      std::string data = this->update_json(obj, detail);
+      std::string data = this->update_json_(obj, detail);
       request->send(200, "application/json", data.c_str());
       return;
     }
@@ -1782,13 +1782,13 @@ void WebServer::handle_update_request(AsyncWebServerRequest *request, const UrlM
 }
 std::string WebServer::update_state_json_generator(WebServer *web_server, void *source) {
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-  return web_server->update_json((update::UpdateEntity *) (source), DETAIL_STATE);
+  return web_server->update_json_((update::UpdateEntity *) (source), DETAIL_STATE);
 }
 std::string WebServer::update_all_json_generator(WebServer *web_server, void *source) {
   // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-  return web_server->update_json((update::UpdateEntity *) (source), DETAIL_STATE);
+  return web_server->update_json_((update::UpdateEntity *) (source), DETAIL_STATE);
 }
-std::string WebServer::update_json(update::UpdateEntity *obj, JsonDetail start_config) {
+std::string WebServer::update_json_(update::UpdateEntity *obj, JsonDetail start_config) {
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   json::JsonBuilder builder;
   JsonObject root = builder.root();
diff --git a/esphome/components/web_server/web_server.h b/esphome/components/web_server/web_server.h
index 98234ec1ae..0078146284 100644
--- a/esphome/components/web_server/web_server.h
+++ b/esphome/components/web_server/web_server.h
@@ -271,8 +271,6 @@ class WebServer : public Controller,
 
   static std::string sensor_state_json_generator(WebServer *web_server, void *source);
   static std::string sensor_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the sensor state with its value as a JSON string.
-  std::string sensor_json(sensor::Sensor *obj, float value, JsonDetail start_config);
 #endif
 
 #ifdef USE_SWITCH
@@ -283,8 +281,6 @@ class WebServer : public Controller,
 
   static std::string switch_state_json_generator(WebServer *web_server, void *source);
   static std::string switch_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the switch state with its value as a JSON string.
-  std::string switch_json(switch_::Switch *obj, bool value, JsonDetail start_config);
 #endif
 
 #ifdef USE_BUTTON
@@ -293,8 +289,6 @@ class WebServer : public Controller,
 
   static std::string button_state_json_generator(WebServer *web_server, void *source);
   static std::string button_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the button details with its value as a JSON string.
-  std::string button_json(button::Button *obj, JsonDetail start_config);
 #endif
 
 #ifdef USE_BINARY_SENSOR
@@ -305,8 +299,6 @@ class WebServer : public Controller,
 
   static std::string binary_sensor_state_json_generator(WebServer *web_server, void *source);
   static std::string binary_sensor_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the binary sensor state with its value as a JSON string.
-  std::string binary_sensor_json(binary_sensor::BinarySensor *obj, bool value, JsonDetail start_config);
 #endif
 
 #ifdef USE_FAN
@@ -317,8 +309,6 @@ class WebServer : public Controller,
 
   static std::string fan_state_json_generator(WebServer *web_server, void *source);
   static std::string fan_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the fan state as a JSON string.
-  std::string fan_json(fan::Fan *obj, JsonDetail start_config);
 #endif
 
 #ifdef USE_LIGHT
@@ -329,8 +319,6 @@ class WebServer : public Controller,
 
   static std::string light_state_json_generator(WebServer *web_server, void *source);
   static std::string light_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the light state as a JSON string.
-  std::string light_json(light::LightState *obj, JsonDetail start_config);
 #endif
 
 #ifdef USE_TEXT_SENSOR
@@ -341,8 +329,6 @@ class WebServer : public Controller,
 
   static std::string text_sensor_state_json_generator(WebServer *web_server, void *source);
   static std::string text_sensor_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the text sensor state with its value as a JSON string.
-  std::string text_sensor_json(text_sensor::TextSensor *obj, const std::string &value, JsonDetail start_config);
 #endif
 
 #ifdef USE_COVER
@@ -353,8 +339,6 @@ class WebServer : public Controller,
 
   static std::string cover_state_json_generator(WebServer *web_server, void *source);
   static std::string cover_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the cover state as a JSON string.
-  std::string cover_json(cover::Cover *obj, JsonDetail start_config);
 #endif
 
 #ifdef USE_NUMBER
@@ -364,8 +348,6 @@ class WebServer : public Controller,
 
   static std::string number_state_json_generator(WebServer *web_server, void *source);
   static std::string number_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the number state with its value as a JSON string.
-  std::string number_json(number::Number *obj, float value, JsonDetail start_config);
 #endif
 
 #ifdef USE_DATETIME_DATE
@@ -375,8 +357,6 @@ class WebServer : public Controller,
 
   static std::string date_state_json_generator(WebServer *web_server, void *source);
   static std::string date_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the date state with its value as a JSON string.
-  std::string date_json(datetime::DateEntity *obj, JsonDetail start_config);
 #endif
 
 #ifdef USE_DATETIME_TIME
@@ -386,8 +366,6 @@ class WebServer : public Controller,
 
   static std::string time_state_json_generator(WebServer *web_server, void *source);
   static std::string time_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the time state with its value as a JSON string.
-  std::string time_json(datetime::TimeEntity *obj, JsonDetail start_config);
 #endif
 
 #ifdef USE_DATETIME_DATETIME
@@ -397,8 +375,6 @@ class WebServer : public Controller,
 
   static std::string datetime_state_json_generator(WebServer *web_server, void *source);
   static std::string datetime_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the datetime state with its value as a JSON string.
-  std::string datetime_json(datetime::DateTimeEntity *obj, JsonDetail start_config);
 #endif
 
 #ifdef USE_TEXT
@@ -408,8 +384,6 @@ class WebServer : public Controller,
 
   static std::string text_state_json_generator(WebServer *web_server, void *source);
   static std::string text_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the text state with its value as a JSON string.
-  std::string text_json(text::Text *obj, const std::string &value, JsonDetail start_config);
 #endif
 
 #ifdef USE_SELECT
@@ -419,8 +393,6 @@ class WebServer : public Controller,
 
   static std::string select_state_json_generator(WebServer *web_server, void *source);
   static std::string select_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the select state with its value as a JSON string.
-  std::string select_json(select::Select *obj, const char *value, JsonDetail start_config);
 #endif
 
 #ifdef USE_CLIMATE
@@ -430,8 +402,6 @@ class WebServer : public Controller,
 
   static std::string climate_state_json_generator(WebServer *web_server, void *source);
   static std::string climate_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the climate details
-  std::string climate_json(climate::Climate *obj, JsonDetail start_config);
 #endif
 
 #ifdef USE_LOCK
@@ -442,8 +412,6 @@ class WebServer : public Controller,
 
   static std::string lock_state_json_generator(WebServer *web_server, void *source);
   static std::string lock_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the lock state with its value as a JSON string.
-  std::string lock_json(lock::Lock *obj, lock::LockState value, JsonDetail start_config);
 #endif
 
 #ifdef USE_VALVE
@@ -454,8 +422,6 @@ class WebServer : public Controller,
 
   static std::string valve_state_json_generator(WebServer *web_server, void *source);
   static std::string valve_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the valve state as a JSON string.
-  std::string valve_json(valve::Valve *obj, JsonDetail start_config);
 #endif
 
 #ifdef USE_ALARM_CONTROL_PANEL
@@ -466,9 +432,6 @@ class WebServer : public Controller,
 
   static std::string alarm_control_panel_state_json_generator(WebServer *web_server, void *source);
   static std::string alarm_control_panel_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the alarm_control_panel state with its value as a JSON string.
-  std::string alarm_control_panel_json(alarm_control_panel::AlarmControlPanel *obj,
-                                       alarm_control_panel::AlarmControlPanelState value, JsonDetail start_config);
 #endif
 
 #ifdef USE_EVENT
@@ -479,9 +442,6 @@ class WebServer : public Controller,
 
   /// Handle a event request under '/event<id>'.
   void handle_event_request(AsyncWebServerRequest *request, const UrlMatch &match);
-
-  /// Dump the event details with its value as a JSON string.
-  std::string event_json(event::Event *obj, const std::string &event_type, JsonDetail start_config);
 #endif
 
 #ifdef USE_UPDATE
@@ -492,8 +452,6 @@ class WebServer : public Controller,
 
   static std::string update_state_json_generator(WebServer *web_server, void *source);
   static std::string update_all_json_generator(WebServer *web_server, void *source);
-  /// Dump the update state with its value as a JSON string.
-  std::string update_json(update::UpdateEntity *obj, JsonDetail start_config);
 #endif
 
   /// Override the web handler's canHandle method.
@@ -593,6 +551,69 @@ class WebServer : public Controller,
   const char *js_include_{nullptr};
 #endif
   bool expose_log_{true};
+
+ private:
+#ifdef USE_SENSOR
+  std::string sensor_json_(sensor::Sensor *obj, float value, JsonDetail start_config);
+#endif
+#ifdef USE_SWITCH
+  std::string switch_json_(switch_::Switch *obj, bool value, JsonDetail start_config);
+#endif
+#ifdef USE_BUTTON
+  std::string button_json_(button::Button *obj, JsonDetail start_config);
+#endif
+#ifdef USE_BINARY_SENSOR
+  std::string binary_sensor_json_(binary_sensor::BinarySensor *obj, bool value, JsonDetail start_config);
+#endif
+#ifdef USE_FAN
+  std::string fan_json_(fan::Fan *obj, JsonDetail start_config);
+#endif
+#ifdef USE_LIGHT
+  std::string light_json_(light::LightState *obj, JsonDetail start_config);
+#endif
+#ifdef USE_TEXT_SENSOR
+  std::string text_sensor_json_(text_sensor::TextSensor *obj, const std::string &value, JsonDetail start_config);
+#endif
+#ifdef USE_COVER
+  std::string cover_json_(cover::Cover *obj, JsonDetail start_config);
+#endif
+#ifdef USE_NUMBER
+  std::string number_json_(number::Number *obj, float value, JsonDetail start_config);
+#endif
+#ifdef USE_DATETIME_DATE
+  std::string date_json_(datetime::DateEntity *obj, JsonDetail start_config);
+#endif
+#ifdef USE_DATETIME_TIME
+  std::string time_json_(datetime::TimeEntity *obj, JsonDetail start_config);
+#endif
+#ifdef USE_DATETIME_DATETIME
+  std::string datetime_json_(datetime::DateTimeEntity *obj, JsonDetail start_config);
+#endif
+#ifdef USE_TEXT
+  std::string text_json_(text::Text *obj, const std::string &value, JsonDetail start_config);
+#endif
+#ifdef USE_SELECT
+  std::string select_json_(select::Select *obj, const char *value, JsonDetail start_config);
+#endif
+#ifdef USE_CLIMATE
+  std::string climate_json_(climate::Climate *obj, JsonDetail start_config);
+#endif
+#ifdef USE_LOCK
+  std::string lock_json_(lock::Lock *obj, lock::LockState value, JsonDetail start_config);
+#endif
+#ifdef USE_VALVE
+  std::string valve_json_(valve::Valve *obj, JsonDetail start_config);
+#endif
+#ifdef USE_ALARM_CONTROL_PANEL
+  std::string alarm_control_panel_json_(alarm_control_panel::AlarmControlPanel *obj,
+                                        alarm_control_panel::AlarmControlPanelState value, JsonDetail start_config);
+#endif
+#ifdef USE_EVENT
+  std::string event_json_(event::Event *obj, const std::string &event_type, JsonDetail start_config);
+#endif
+#ifdef USE_UPDATE
+  std::string update_json_(update::UpdateEntity *obj, JsonDetail start_config);
+#endif
 };
 
 }  // namespace web_server

From f238f9331272c25bf073b921f443e62e75c73c6c Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Mon, 22 Dec 2025 11:37:51 -1000
Subject: [PATCH 4/5] [core] Move comment to PROGMEM on ESP8266 (#12554)

---
 esphome/components/web_server/web_server.cpp |  4 +-
 esphome/core/application.h                   | 23 +++---
 esphome/core/build_info_data.h               |  2 +
 esphome/core/config.py                       |  3 +-
 esphome/writer.py                            | 25 +++++--
 tests/dummy_main.cpp                         |  2 +-
 tests/unit_tests/test_writer.py              | 76 +++++++++++++++++---
 7 files changed, 105 insertions(+), 30 deletions(-)

diff --git a/esphome/components/web_server/web_server.cpp b/esphome/components/web_server/web_server.cpp
index ece9d65121..b0731f335b 100644
--- a/esphome/components/web_server/web_server.cpp
+++ b/esphome/components/web_server/web_server.cpp
@@ -287,7 +287,9 @@ std::string WebServer::get_config_json() {
   JsonObject root = builder.root();
 
   root[ESPHOME_F("title")] = App.get_friendly_name().empty() ? App.get_name() : App.get_friendly_name();
-  root[ESPHOME_F("comment")] = App.get_comment_ref();
+  char comment_buffer[ESPHOME_COMMENT_SIZE];
+  App.get_comment_string(comment_buffer);
+  root[ESPHOME_F("comment")] = comment_buffer;
 #if defined(USE_WEBSERVER_OTA_DISABLED) || !defined(USE_WEBSERVER_OTA)
   root[ESPHOME_F("ota")] = false;  // Note: USE_WEBSERVER_OTA_DISABLED only affects web_server, not captive_portal
 #else
diff --git a/esphome/core/application.h b/esphome/core/application.h
index d2146a6c16..13461b3ebd 100644
--- a/esphome/core/application.h
+++ b/esphome/core/application.h
@@ -12,6 +12,7 @@
 #include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/preferences.h"
+#include "esphome/core/progmem.h"
 #include "esphome/core/scheduler.h"
 #include "esphome/core/string_ref.h"
 #include "esphome/core/version.h"
@@ -107,8 +108,7 @@ static const uint32_t TEARDOWN_TIMEOUT_REBOOT_MS = 1000;  // 1 second for quick
 
 class Application {
  public:
-  void pre_setup(const std::string &name, const std::string &friendly_name, const char *comment,
-                 bool name_add_mac_suffix) {
+  void pre_setup(const std::string &name, const std::string &friendly_name, bool name_add_mac_suffix) {
     arch_init();
     this->name_add_mac_suffix_ = name_add_mac_suffix;
     if (name_add_mac_suffix) {
@@ -127,7 +127,6 @@ class Application {
       this->name_ = name;
       this->friendly_name_ = friendly_name;
     }
-    this->comment_ = comment;
   }
 
 #ifdef USE_DEVICES
@@ -264,10 +263,19 @@ class Application {
     return "";
   }
 
-  /// Get the comment of this Application set by pre_setup().
-  std::string get_comment() const { return this->comment_; }
-  /// Get the comment as StringRef (avoids allocation)
-  StringRef get_comment_ref() const { return StringRef(this->comment_); }
+  /// Copy the comment string into the provided buffer
+  /// Buffer must be ESPHOME_COMMENT_SIZE bytes (compile-time enforced)
+  void get_comment_string(std::span<char, ESPHOME_COMMENT_SIZE> buffer) {
+    ESPHOME_strncpy_P(buffer.data(), ESPHOME_COMMENT_STR, buffer.size());
+    buffer[buffer.size() - 1] = '\0';
+  }
+
+  /// Get the comment of this Application as a string
+  std::string get_comment() {
+    char buffer[ESPHOME_COMMENT_SIZE];
+    this->get_comment_string(buffer);
+    return std::string(buffer);
+  }
 
   bool is_name_add_mac_suffix_enabled() const { return this->name_add_mac_suffix_; }
 
@@ -513,7 +521,6 @@ class Application {
 
   // Pointer-sized members first
   Component *current_component_{nullptr};
-  const char *comment_{nullptr};
 
   // std::vector (3 pointers each: begin, end, capacity)
   // Partitioned vector design for looping components
diff --git a/esphome/core/build_info_data.h b/esphome/core/build_info_data.h
index 5e424ffaca..02bb465e44 100644
--- a/esphome/core/build_info_data.h
+++ b/esphome/core/build_info_data.h
@@ -7,4 +7,6 @@
 
 #define ESPHOME_CONFIG_HASH 0x12345678U  // NOLINT
 #define ESPHOME_BUILD_TIME 1700000000    // NOLINT
+#define ESPHOME_COMMENT_SIZE 1           // NOLINT
 static const char ESPHOME_BUILD_TIME_STR[] = "2024-01-01 00:00:00 +0000";
+static const char ESPHOME_COMMENT_STR[] = "";
diff --git a/esphome/core/config.py b/esphome/core/config.py
index 507a39b401..5e32b9380d 100644
--- a/esphome/core/config.py
+++ b/esphome/core/config.py
@@ -209,7 +209,7 @@ CONFIG_SCHEMA = cv.All(
             cv.Required(CONF_NAME): cv.valid_name,
             cv.Optional(CONF_FRIENDLY_NAME, ""): cv.All(cv.string, cv.Length(max=120)),
             cv.Optional(CONF_AREA): validate_area_config,
-            cv.Optional(CONF_COMMENT): cv.string,
+            cv.Optional(CONF_COMMENT): cv.All(cv.string, cv.Length(max=255)),
             cv.Required(CONF_BUILD_PATH): cv.string,
             cv.Optional(CONF_PLATFORMIO_OPTIONS, default={}): cv.Schema(
                 {
@@ -505,7 +505,6 @@ async def to_code(config: ConfigType) -> None:
         cg.App.pre_setup(
             config[CONF_NAME],
             config[CONF_FRIENDLY_NAME],
-            config.get(CONF_COMMENT, ""),
             config[CONF_NAME_ADD_MAC_SUFFIX],
         )
     )
diff --git a/esphome/writer.py b/esphome/writer.py
index 183fff8730..9ae40e417a 100644
--- a/esphome/writer.py
+++ b/esphome/writer.py
@@ -21,6 +21,7 @@ from esphome.const import (
 from esphome.core import CORE, EsphomeError
 from esphome.helpers import (
     copy_file_if_changed,
+    cpp_string_escape,
     get_str_env,
     is_ha_addon,
     read_file,
@@ -271,7 +272,7 @@ def copy_src_tree():
         "esphome", "core", "build_info_data.h"
     )
     build_info_json_path = CORE.relative_build_path("build_info.json")
-    config_hash, build_time, build_time_str = get_build_info()
+    config_hash, build_time, build_time_str, comment = get_build_info()
 
     # Defensively force a rebuild if the build_info files don't exist, or if
     # there was a config change which didn't actually cause a source change
@@ -292,7 +293,9 @@ def copy_src_tree():
     if sources_changed:
         write_file(
             build_info_data_h_path,
-            generate_build_info_data_h(config_hash, build_time, build_time_str),
+            generate_build_info_data_h(
+                config_hash, build_time, build_time_str, comment
+            ),
         )
         write_file(
             build_info_json_path,
@@ -332,31 +335,39 @@ def generate_version_h():
     )
 
 
-def get_build_info() -> tuple[int, int, str]:
+def get_build_info() -> tuple[int, int, str, str]:
     """Calculate build_info values from current config.
 
     Returns:
-        Tuple of (config_hash, build_time, build_time_str)
+        Tuple of (config_hash, build_time, build_time_str, comment)
     """
     config_hash = CORE.config_hash
     build_time = int(time.time())
     build_time_str = time.strftime("%Y-%m-%d %H:%M:%S %z", time.localtime(build_time))
-    return config_hash, build_time, build_time_str
+    comment = CORE.comment or ""
+    return config_hash, build_time, build_time_str, comment
 
 
 def generate_build_info_data_h(
-    config_hash: int, build_time: int, build_time_str: str
+    config_hash: int, build_time: int, build_time_str: str, comment: str
 ) -> str:
-    """Generate build_info_data.h header with config hash and build time."""
+    """Generate build_info_data.h header with config hash, build time, and comment."""
+    # cpp_string_escape returns '"escaped"', slice off the quotes since template has them
+    escaped_comment = cpp_string_escape(comment)[1:-1]
+    # +1 for null terminator
+    comment_size = len(comment) + 1
     return f"""#pragma once
 // Auto-generated build_info data
 #define ESPHOME_CONFIG_HASH 0x{config_hash:08x}U  // NOLINT
 #define ESPHOME_BUILD_TIME {build_time}  // NOLINT
+#define ESPHOME_COMMENT_SIZE {comment_size}  // NOLINT
 #ifdef USE_ESP8266
 #include <pgmspace.h>
 static const char ESPHOME_BUILD_TIME_STR[] PROGMEM = "{build_time_str}";
+static const char ESPHOME_COMMENT_STR[] PROGMEM = "{escaped_comment}";
 #else
 static const char ESPHOME_BUILD_TIME_STR[] = "{build_time_str}";
+static const char ESPHOME_COMMENT_STR[] = "{escaped_comment}";
 #endif
 """
 
diff --git a/tests/dummy_main.cpp b/tests/dummy_main.cpp
index 5849f4eb95..e6fe733807 100644
--- a/tests/dummy_main.cpp
+++ b/tests/dummy_main.cpp
@@ -12,7 +12,7 @@
 using namespace esphome;
 
 void setup() {
-  App.pre_setup("livingroom", "LivingRoom", "comment", false);
+  App.pre_setup("livingroom", "LivingRoom", false);
   auto *log = new logger::Logger(115200, 512);  // NOLINT
   log->pre_setup();
   log->set_uart_selection(logger::UART_SELECTION_UART0);
diff --git a/tests/unit_tests/test_writer.py b/tests/unit_tests/test_writer.py
index 06a7d5dbdf..f354d71bb7 100644
--- a/tests/unit_tests/test_writer.py
+++ b/tests/unit_tests/test_writer.py
@@ -1186,8 +1186,9 @@ def test_get_build_info_new_build(
     build_info_path = tmp_path / "build_info.json"
     mock_core.relative_build_path.return_value = build_info_path
     mock_core.config_hash = 0x12345678
+    mock_core.comment = "Test comment"
 
-    config_hash, build_time, build_time_str = get_build_info()
+    config_hash, build_time, build_time_str, comment = get_build_info()
 
     assert config_hash == 0x12345678
     assert isinstance(build_time, int)
@@ -1195,6 +1196,7 @@ def test_get_build_info_new_build(
     assert isinstance(build_time_str, str)
     # Verify build_time_str format matches expected pattern
     assert len(build_time_str) >= 19  # e.g., "2025-12-15 16:27:44 +0000"
+    assert comment == "Test comment"
 
 
 @patch("esphome.writer.CORE")
@@ -1206,6 +1208,7 @@ def test_get_build_info_always_returns_current_time(
     build_info_path = tmp_path / "build_info.json"
     mock_core.relative_build_path.return_value = build_info_path
     mock_core.config_hash = 0x12345678
+    mock_core.comment = ""
 
     # Create existing build_info.json with matching config_hash and version
     existing_build_time = 1700000000
@@ -1222,7 +1225,7 @@ def test_get_build_info_always_returns_current_time(
     )
 
     with patch("esphome.writer.__version__", "2025.1.0-dev"):
-        config_hash, build_time, build_time_str = get_build_info()
+        config_hash, build_time, build_time_str, comment = get_build_info()
 
     assert config_hash == 0x12345678
     # get_build_info now always returns current time
@@ -1240,6 +1243,7 @@ def test_get_build_info_config_changed(
     build_info_path = tmp_path / "build_info.json"
     mock_core.relative_build_path.return_value = build_info_path
     mock_core.config_hash = 0xABCDEF00  # Different from existing
+    mock_core.comment = ""
 
     # Create existing build_info.json with different config_hash
     existing_build_time = 1700000000
@@ -1255,7 +1259,7 @@ def test_get_build_info_config_changed(
     )
 
     with patch("esphome.writer.__version__", "2025.1.0-dev"):
-        config_hash, build_time, build_time_str = get_build_info()
+        config_hash, build_time, build_time_str, comment = get_build_info()
 
     assert config_hash == 0xABCDEF00
     assert build_time != existing_build_time  # New time generated
@@ -1271,6 +1275,7 @@ def test_get_build_info_version_changed(
     build_info_path = tmp_path / "build_info.json"
     mock_core.relative_build_path.return_value = build_info_path
     mock_core.config_hash = 0x12345678
+    mock_core.comment = ""
 
     # Create existing build_info.json with different version
     existing_build_time = 1700000000
@@ -1286,7 +1291,7 @@ def test_get_build_info_version_changed(
     )
 
     with patch("esphome.writer.__version__", "2025.1.0-dev"):  # New version
-        config_hash, build_time, build_time_str = get_build_info()
+        config_hash, build_time, build_time_str, comment = get_build_info()
 
     assert config_hash == 0x12345678
     assert build_time != existing_build_time  # New time generated
@@ -1302,11 +1307,12 @@ def test_get_build_info_invalid_json(
     build_info_path = tmp_path / "build_info.json"
     mock_core.relative_build_path.return_value = build_info_path
     mock_core.config_hash = 0x12345678
+    mock_core.comment = ""
 
     # Create invalid JSON file
     build_info_path.write_text("not valid json {{{")
 
-    config_hash, build_time, build_time_str = get_build_info()
+    config_hash, build_time, build_time_str, comment = get_build_info()
 
     assert config_hash == 0x12345678
     assert isinstance(build_time, int)
@@ -1322,12 +1328,13 @@ def test_get_build_info_missing_keys(
     build_info_path = tmp_path / "build_info.json"
     mock_core.relative_build_path.return_value = build_info_path
     mock_core.config_hash = 0x12345678
+    mock_core.comment = ""
 
     # Create JSON with missing keys
     build_info_path.write_text(json.dumps({"config_hash": 0x12345678}))
 
     with patch("esphome.writer.__version__", "2025.1.0-dev"):
-        config_hash, build_time, build_time_str = get_build_info()
+        config_hash, build_time, build_time_str, comment = get_build_info()
 
     assert config_hash == 0x12345678
     assert isinstance(build_time, int)
@@ -1343,8 +1350,9 @@ def test_get_build_info_build_time_str_format(
     build_info_path = tmp_path / "build_info.json"
     mock_core.relative_build_path.return_value = build_info_path
     mock_core.config_hash = 0x12345678
+    mock_core.comment = ""
 
-    config_hash, build_time, build_time_str = get_build_info()
+    config_hash, build_time, build_time_str, comment = get_build_info()
 
     # Verify the format matches "%Y-%m-%d %H:%M:%S %z"
     # e.g., "2025-12-15 16:27:44 +0000"
@@ -1357,36 +1365,73 @@ def test_generate_build_info_data_h_format() -> None:
     config_hash = 0x12345678
     build_time = 1700000000
     build_time_str = "2023-11-14 22:13:20 +0000"
+    comment = "Test comment"
 
-    result = generate_build_info_data_h(config_hash, build_time, build_time_str)
+    result = generate_build_info_data_h(
+        config_hash, build_time, build_time_str, comment
+    )
 
     assert "#pragma once" in result
     assert "#define ESPHOME_CONFIG_HASH 0x12345678U" in result
     assert "#define ESPHOME_BUILD_TIME 1700000000" in result
+    assert "#define ESPHOME_COMMENT_SIZE 13" in result  # len("Test comment") + 1
     assert 'ESPHOME_BUILD_TIME_STR[] = "2023-11-14 22:13:20 +0000"' in result
+    assert 'ESPHOME_COMMENT_STR[] = "Test comment"' in result
 
 
 def test_generate_build_info_data_h_esp8266_progmem() -> None:
     """Test generate_build_info_data_h includes PROGMEM for ESP8266."""
-    result = generate_build_info_data_h(0xABCDEF01, 1700000000, "test")
+    result = generate_build_info_data_h(0xABCDEF01, 1700000000, "test", "comment")
 
     # Should have ESP8266 PROGMEM conditional
     assert "#ifdef USE_ESP8266" in result
     assert "#include <pgmspace.h>" in result
     assert "PROGMEM" in result
+    # Both build time and comment should have PROGMEM versions
+    assert 'ESPHOME_BUILD_TIME_STR[] PROGMEM = "test"' in result
+    assert 'ESPHOME_COMMENT_STR[] PROGMEM = "comment"' in result
 
 
 def test_generate_build_info_data_h_hash_formatting() -> None:
     """Test generate_build_info_data_h formats hash with leading zeros."""
     # Test with small hash value that needs leading zeros
-    result = generate_build_info_data_h(0x00000001, 0, "test")
+    result = generate_build_info_data_h(0x00000001, 0, "test", "")
     assert "#define ESPHOME_CONFIG_HASH 0x00000001U" in result
 
     # Test with larger hash value
-    result = generate_build_info_data_h(0xFFFFFFFF, 0, "test")
+    result = generate_build_info_data_h(0xFFFFFFFF, 0, "test", "")
     assert "#define ESPHOME_CONFIG_HASH 0xffffffffU" in result
 
 
+def test_generate_build_info_data_h_comment_escaping() -> None:
+    r"""Test generate_build_info_data_h properly escapes special characters in comment.
+
+    Uses cpp_string_escape which outputs octal escapes for special characters:
+    - backslash (ASCII 92) -> \134
+    - double quote (ASCII 34) -> \042
+    - newline (ASCII 10) -> \012
+    """
+    # Test backslash escaping (ASCII 92 = octal 134)
+    result = generate_build_info_data_h(0, 0, "test", "backslash\\here")
+    assert 'ESPHOME_COMMENT_STR[] = "backslash\\134here"' in result
+
+    # Test quote escaping (ASCII 34 = octal 042)
+    result = generate_build_info_data_h(0, 0, "test", 'has "quotes"')
+    assert 'ESPHOME_COMMENT_STR[] = "has \\042quotes\\042"' in result
+
+    # Test newline escaping (ASCII 10 = octal 012)
+    result = generate_build_info_data_h(0, 0, "test", "line1\nline2")
+    assert 'ESPHOME_COMMENT_STR[] = "line1\\012line2"' in result
+
+
+def test_generate_build_info_data_h_empty_comment() -> None:
+    """Test generate_build_info_data_h handles empty comment."""
+    result = generate_build_info_data_h(0, 0, "test", "")
+
+    assert "#define ESPHOME_COMMENT_SIZE 1" in result  # Just null terminator
+    assert 'ESPHOME_COMMENT_STR[] = ""' in result
+
+
 @patch("esphome.writer.CORE")
 @patch("esphome.writer.iter_components")
 @patch("esphome.writer.walk_files")
@@ -1445,6 +1490,7 @@ def test_copy_src_tree_writes_build_info_files(
     mock_core.relative_build_path.side_effect = lambda *args: build_path.joinpath(*args)
     mock_core.defines = []
     mock_core.config_hash = 0xDEADBEEF
+    mock_core.comment = "Test comment"
     mock_core.target_platform = "test_platform"
     mock_core.config = {}
     mock_iter_components.return_value = [("core", mock_component)]
@@ -1466,6 +1512,8 @@ def test_copy_src_tree_writes_build_info_files(
     assert "#define ESPHOME_CONFIG_HASH 0xdeadbeefU" in build_info_h_content
     assert "#define ESPHOME_BUILD_TIME" in build_info_h_content
     assert "ESPHOME_BUILD_TIME_STR" in build_info_h_content
+    assert "#define ESPHOME_COMMENT_SIZE" in build_info_h_content
+    assert "ESPHOME_COMMENT_STR" in build_info_h_content
 
     # Verify build_info.json was written
     build_info_json_path = build_path / "build_info.json"
@@ -1517,6 +1565,7 @@ def test_copy_src_tree_detects_config_hash_change(
     mock_core.relative_build_path.side_effect = lambda *args: build_path.joinpath(*args)
     mock_core.defines = []
     mock_core.config_hash = 0xDEADBEEF  # Different from existing
+    mock_core.comment = ""
     mock_core.target_platform = "test_platform"
     mock_core.config = {}
     mock_iter_components.return_value = []
@@ -1578,6 +1627,7 @@ def test_copy_src_tree_detects_version_change(
     mock_core.relative_build_path.side_effect = lambda *args: build_path.joinpath(*args)
     mock_core.defines = []
     mock_core.config_hash = 0xDEADBEEF
+    mock_core.comment = ""
     mock_core.target_platform = "test_platform"
     mock_core.config = {}
     mock_iter_components.return_value = []
@@ -1627,6 +1677,7 @@ def test_copy_src_tree_handles_invalid_build_info_json(
     mock_core.relative_build_path.side_effect = lambda *args: build_path.joinpath(*args)
     mock_core.defines = []
     mock_core.config_hash = 0xDEADBEEF
+    mock_core.comment = ""
     mock_core.target_platform = "test_platform"
     mock_core.config = {}
     mock_iter_components.return_value = []
@@ -1700,6 +1751,7 @@ def test_copy_src_tree_build_info_timestamp_behavior(
     mock_core.relative_build_path.side_effect = lambda *args: build_path.joinpath(*args)
     mock_core.defines = []
     mock_core.config_hash = 0xDEADBEEF
+    mock_core.comment = ""
     mock_core.target_platform = "test_platform"
     mock_core.config = {}
     mock_iter_components.return_value = [("test", mock_component)]
@@ -1794,6 +1846,7 @@ def test_copy_src_tree_detects_removed_source_file(
     mock_core.relative_build_path.side_effect = lambda *args: build_path.joinpath(*args)
     mock_core.defines = []
     mock_core.config_hash = 0xDEADBEEF
+    mock_core.comment = ""
     mock_core.target_platform = "test_platform"
     mock_core.config = {}
     mock_iter_components.return_value = []  # No components = file should be removed
@@ -1855,6 +1908,7 @@ def test_copy_src_tree_ignores_removed_generated_file(
     mock_core.relative_build_path.side_effect = lambda *args: build_path.joinpath(*args)
     mock_core.defines = []
     mock_core.config_hash = 0xDEADBEEF
+    mock_core.comment = ""
     mock_core.target_platform = "test_platform"
     mock_core.config = {}
     mock_iter_components.return_value = []

From af0d4d2c2cfd6c955bd2903af7a4039d7793c1cf Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Mon, 22 Dec 2025 11:56:07 -1000
Subject: [PATCH 5/5] [web_server] Use stack buffers for value formatting to
 reduce flash usage (#12575)

---
 esphome/components/web_server/web_server.cpp | 68 +++++++++++---------
 esphome/core/helpers.cpp                     | 34 ++++++----
 esphome/core/helpers.h                       | 11 +++-
 3 files changed, 68 insertions(+), 45 deletions(-)

diff --git a/esphome/components/web_server/web_server.cpp b/esphome/components/web_server/web_server.cpp
index b0731f335b..df8a5364cf 100644
--- a/esphome/components/web_server/web_server.cpp
+++ b/esphome/components/web_server/web_server.cpp
@@ -432,7 +432,7 @@ static void set_json_value(JsonObject &root, EntityBase *obj, const char *prefix
 }
 
 template<typename T>
-static void set_json_icon_state_value(JsonObject &root, EntityBase *obj, const char *prefix, const std::string &state,
+static void set_json_icon_state_value(JsonObject &root, EntityBase *obj, const char *prefix, const char *state,
                                       const T &value, JsonDetail start_config) {
   set_json_value(root, obj, prefix, value, start_config);
   root[ESPHOME_F("state")] = state;
@@ -475,9 +475,10 @@ std::string WebServer::sensor_json_(sensor::Sensor *obj, float value, JsonDetail
   JsonObject root = builder.root();
 
   const auto uom_ref = obj->get_unit_of_measurement_ref();
-
-  std::string state =
-      std::isnan(value) ? "NA" : value_accuracy_with_uom_to_string(value, obj->get_accuracy_decimals(), uom_ref);
+  char buf[VALUE_ACCURACY_MAX_LEN];
+  const char *state = std::isnan(value)
+                          ? "NA"
+                          : (value_accuracy_with_uom_to_buf(buf, value, obj->get_accuracy_decimals(), uom_ref), buf);
   set_json_icon_state_value(root, obj, "sensor", state, value, start_config);
   if (start_config == DETAIL_ALL) {
     this->add_sorting_info_(root, obj);
@@ -522,7 +523,7 @@ std::string WebServer::text_sensor_json_(text_sensor::TextSensor *obj, const std
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
-  set_json_icon_state_value(root, obj, "text_sensor", value, value, start_config);
+  set_json_icon_state_value(root, obj, "text_sensor", value.c_str(), value.c_str(), start_config);
   if (start_config == DETAIL_ALL) {
     this->add_sorting_info_(root, obj);
   }
@@ -974,21 +975,20 @@ std::string WebServer::number_json_(number::Number *obj, float value, JsonDetail
   JsonObject root = builder.root();
 
   const auto uom_ref = obj->traits.get_unit_of_measurement_ref();
+  const int8_t accuracy = step_to_accuracy_decimals(obj->traits.get_step());
 
-  std::string val_str = std::isnan(value)
-                            ? "\"NaN\""
-                            : value_accuracy_to_string(value, step_to_accuracy_decimals(obj->traits.get_step()));
-  std::string state_str = std::isnan(value) ? "NA"
-                                            : value_accuracy_with_uom_to_string(
-                                                  value, step_to_accuracy_decimals(obj->traits.get_step()), uom_ref);
+  // Need two buffers: one for value, one for state with UOM
+  char val_buf[VALUE_ACCURACY_MAX_LEN];
+  char state_buf[VALUE_ACCURACY_MAX_LEN];
+  const char *val_str = std::isnan(value) ? "\"NaN\"" : (value_accuracy_to_buf(val_buf, value, accuracy), val_buf);
+  const char *state_str =
+      std::isnan(value) ? "NA" : (value_accuracy_with_uom_to_buf(state_buf, value, accuracy, uom_ref), state_buf);
   set_json_icon_state_value(root, obj, "number", state_str, val_str, start_config);
   if (start_config == DETAIL_ALL) {
-    root[ESPHOME_F("min_value")] =
-        value_accuracy_to_string(obj->traits.get_min_value(), step_to_accuracy_decimals(obj->traits.get_step()));
-    root[ESPHOME_F("max_value")] =
-        value_accuracy_to_string(obj->traits.get_max_value(), step_to_accuracy_decimals(obj->traits.get_step()));
-    root[ESPHOME_F("step")] =
-        value_accuracy_to_string(obj->traits.get_step(), step_to_accuracy_decimals(obj->traits.get_step()));
+    // ArduinoJson copies the string immediately, so we can reuse val_buf
+    root[ESPHOME_F("min_value")] = (value_accuracy_to_buf(val_buf, obj->traits.get_min_value(), accuracy), val_buf);
+    root[ESPHOME_F("max_value")] = (value_accuracy_to_buf(val_buf, obj->traits.get_max_value(), accuracy), val_buf);
+    root[ESPHOME_F("step")] = (value_accuracy_to_buf(val_buf, obj->traits.get_step(), accuracy), val_buf);
     root[ESPHOME_F("mode")] = (int) obj->traits.get_mode();
     if (!uom_ref.empty())
       root[ESPHOME_F("uom")] = uom_ref;
@@ -1230,8 +1230,8 @@ std::string WebServer::text_json_(text::Text *obj, const std::string &value, Jso
   json::JsonBuilder builder;
   JsonObject root = builder.root();
 
-  std::string state = obj->traits.get_mode() == text::TextMode::TEXT_MODE_PASSWORD ? "********" : value;
-  set_json_icon_state_value(root, obj, "text", state, value, start_config);
+  const char *state = obj->traits.get_mode() == text::TextMode::TEXT_MODE_PASSWORD ? "********" : value.c_str();
+  set_json_icon_state_value(root, obj, "text", state, value.c_str(), start_config);
   root[ESPHOME_F("min_length")] = obj->traits.get_min_length();
   root[ESPHOME_F("max_length")] = obj->traits.get_max_length();
   root[ESPHOME_F("pattern")] = obj->traits.get_pattern_c_str();
@@ -1359,6 +1359,7 @@ std::string WebServer::climate_json_(climate::Climate *obj, JsonDetail start_con
   int8_t target_accuracy = traits.get_target_temperature_accuracy_decimals();
   int8_t current_accuracy = traits.get_current_temperature_accuracy_decimals();
   char buf[PSTR_LOCAL_SIZE];
+  char temp_buf[VALUE_ACCURACY_MAX_LEN];
 
   if (start_config == DETAIL_ALL) {
     JsonArray opt = root[ESPHOME_F("modes")].to<JsonArray>();
@@ -1395,8 +1396,10 @@ std::string WebServer::climate_json_(climate::Climate *obj, JsonDetail start_con
 
   bool has_state = false;
   root[ESPHOME_F("mode")] = PSTR_LOCAL(climate_mode_to_string(obj->mode));
-  root[ESPHOME_F("max_temp")] = value_accuracy_to_string(traits.get_visual_max_temperature(), target_accuracy);
-  root[ESPHOME_F("min_temp")] = value_accuracy_to_string(traits.get_visual_min_temperature(), target_accuracy);
+  root[ESPHOME_F("max_temp")] =
+      (value_accuracy_to_buf(temp_buf, traits.get_visual_max_temperature(), target_accuracy), temp_buf);
+  root[ESPHOME_F("min_temp")] =
+      (value_accuracy_to_buf(temp_buf, traits.get_visual_min_temperature(), target_accuracy), temp_buf);
   root[ESPHOME_F("step")] = traits.get_visual_target_temperature_step();
   if (traits.has_feature_flags(climate::CLIMATE_SUPPORTS_ACTION)) {
     root[ESPHOME_F("action")] = PSTR_LOCAL(climate_action_to_string(obj->action));
@@ -1419,23 +1422,26 @@ std::string WebServer::climate_json_(climate::Climate *obj, JsonDetail start_con
     root[ESPHOME_F("swing_mode")] = PSTR_LOCAL(climate_swing_mode_to_string(obj->swing_mode));
   }
   if (traits.has_feature_flags(climate::CLIMATE_SUPPORTS_CURRENT_TEMPERATURE)) {
-    if (!std::isnan(obj->current_temperature)) {
-      root[ESPHOME_F("current_temperature")] = value_accuracy_to_string(obj->current_temperature, current_accuracy);
-    } else {
-      root[ESPHOME_F("current_temperature")] = "NA";
-    }
+    root[ESPHOME_F("current_temperature")] =
+        std::isnan(obj->current_temperature)
+            ? "NA"
+            : (value_accuracy_to_buf(temp_buf, obj->current_temperature, current_accuracy), temp_buf);
   }
   if (traits.has_feature_flags(climate::CLIMATE_SUPPORTS_TWO_POINT_TARGET_TEMPERATURE |
                                climate::CLIMATE_REQUIRES_TWO_POINT_TARGET_TEMPERATURE)) {
-    root[ESPHOME_F("target_temperature_low")] = value_accuracy_to_string(obj->target_temperature_low, target_accuracy);
+    root[ESPHOME_F("target_temperature_low")] =
+        (value_accuracy_to_buf(temp_buf, obj->target_temperature_low, target_accuracy), temp_buf);
     root[ESPHOME_F("target_temperature_high")] =
-        value_accuracy_to_string(obj->target_temperature_high, target_accuracy);
+        (value_accuracy_to_buf(temp_buf, obj->target_temperature_high, target_accuracy), temp_buf);
     if (!has_state) {
-      root[ESPHOME_F("state")] = value_accuracy_to_string(
-          (obj->target_temperature_high + obj->target_temperature_low) / 2.0f, target_accuracy);
+      root[ESPHOME_F("state")] =
+          (value_accuracy_to_buf(temp_buf, (obj->target_temperature_high + obj->target_temperature_low) / 2.0f,
+                                 target_accuracy),
+           temp_buf);
     }
   } else {
-    root[ESPHOME_F("target_temperature")] = value_accuracy_to_string(obj->target_temperature, target_accuracy);
+    root[ESPHOME_F("target_temperature")] =
+        (value_accuracy_to_buf(temp_buf, obj->target_temperature, target_accuracy), temp_buf);
     if (!has_state)
       root[ESPHOME_F("state")] = root[ESPHOME_F("target_temperature")];
   }
diff --git a/esphome/core/helpers.cpp b/esphome/core/helpers.cpp
index f55f53f16b..d7d32ea28f 100644
--- a/esphome/core/helpers.cpp
+++ b/esphome/core/helpers.cpp
@@ -383,23 +383,33 @@ static inline void normalize_accuracy_decimals(float &value, int8_t &accuracy_de
 }
 
 std::string value_accuracy_to_string(float value, int8_t accuracy_decimals) {
-  normalize_accuracy_decimals(value, accuracy_decimals);
-  char tmp[32];  // should be enough, but we should maybe improve this at some point.
-  snprintf(tmp, sizeof(tmp), "%.*f", accuracy_decimals, value);
-  return std::string(tmp);
+  char buf[VALUE_ACCURACY_MAX_LEN];
+  value_accuracy_to_buf(buf, value, accuracy_decimals);
+  return std::string(buf);
 }
 
-std::string value_accuracy_with_uom_to_string(float value, int8_t accuracy_decimals, StringRef unit_of_measurement) {
+size_t value_accuracy_to_buf(std::span<char, VALUE_ACCURACY_MAX_LEN> buf, float value, int8_t accuracy_decimals) {
   normalize_accuracy_decimals(value, accuracy_decimals);
-  // Buffer sized for float (up to ~15 chars) + space + typical UOM (usually <20 chars like "μS/cm")
-  // snprintf truncates safely if exceeded, though ESPHome UOMs are typically short
-  char tmp[64];
+  // snprintf returns chars that would be written (excluding null), or negative on error
+  int len = snprintf(buf.data(), buf.size(), "%.*f", accuracy_decimals, value);
+  if (len < 0)
+    return 0;  // encoding error
+  // On truncation, snprintf returns would-be length; actual written is buf.size() - 1
+  return static_cast<size_t>(len) >= buf.size() ? buf.size() - 1 : static_cast<size_t>(len);
+}
+
+size_t value_accuracy_with_uom_to_buf(std::span<char, VALUE_ACCURACY_MAX_LEN> buf, float value,
+                                      int8_t accuracy_decimals, StringRef unit_of_measurement) {
   if (unit_of_measurement.empty()) {
-    snprintf(tmp, sizeof(tmp), "%.*f", accuracy_decimals, value);
-  } else {
-    snprintf(tmp, sizeof(tmp), "%.*f %s", accuracy_decimals, value, unit_of_measurement.c_str());
+    return value_accuracy_to_buf(buf, value, accuracy_decimals);
   }
-  return std::string(tmp);
+  normalize_accuracy_decimals(value, accuracy_decimals);
+  // snprintf returns chars that would be written (excluding null), or negative on error
+  int len = snprintf(buf.data(), buf.size(), "%.*f %s", accuracy_decimals, value, unit_of_measurement.c_str());
+  if (len < 0)
+    return 0;  // encoding error
+  // On truncation, snprintf returns would-be length; actual written is buf.size() - 1
+  return static_cast<size_t>(len) >= buf.size() ? buf.size() - 1 : static_cast<size_t>(len);
 }
 
 int8_t step_to_accuracy_decimals(float step) {
diff --git a/esphome/core/helpers.h b/esphome/core/helpers.h
index b575a14d14..769041160c 100644
--- a/esphome/core/helpers.h
+++ b/esphome/core/helpers.h
@@ -886,8 +886,15 @@ ParseOnOffState parse_on_off(const char *str, const char *on = nullptr, const ch
 
 /// Create a string from a value and an accuracy in decimals.
 std::string value_accuracy_to_string(float value, int8_t accuracy_decimals);
-/// Create a string from a value, an accuracy in decimals, and a unit of measurement.
-std::string value_accuracy_with_uom_to_string(float value, int8_t accuracy_decimals, StringRef unit_of_measurement);
+
+/// Maximum buffer size for value_accuracy formatting (float ~15 chars + space + UOM ~40 chars + null)
+static constexpr size_t VALUE_ACCURACY_MAX_LEN = 64;
+
+/// Format value with accuracy to buffer, returns chars written (excluding null)
+size_t value_accuracy_to_buf(std::span<char, VALUE_ACCURACY_MAX_LEN> buf, float value, int8_t accuracy_decimals);
+/// Format value with accuracy and UOM to buffer, returns chars written (excluding null)
+size_t value_accuracy_with_uom_to_buf(std::span<char, VALUE_ACCURACY_MAX_LEN> buf, float value,
+                                      int8_t accuracy_decimals, StringRef unit_of_measurement);
 
 /// Derive accuracy in decimals from an increment step.
 int8_t step_to_accuracy_decimals(float step);