diff --git a/esphome/components/openthread_info/openthread_info_text_sensor.h b/esphome/components/openthread_info/openthread_info_text_sensor.h
index 35e46212cb..ac5623e0c1 100644
--- a/esphome/components/openthread_info/openthread_info_text_sensor.h
+++ b/esphome/components/openthread_info/openthread_info_text_sensor.h
@@ -33,13 +33,12 @@ class IPAddressOpenThreadInfo : public PollingComponent, public text_sensor::Tex
       return;
     }
 
-    char address_as_string[40];
-    otIp6AddressToString(&*address, address_as_string, 40);
-    std::string ip = address_as_string;
+    char buf[OT_IP6_ADDRESS_STRING_SIZE];
+    otIp6AddressToString(&*address, buf, sizeof(buf));
 
-    if (this->last_ip_ != ip) {
-      this->last_ip_ = ip;
-      this->publish_state(this->last_ip_);
+    if (this->last_ip_ != buf) {
+      this->last_ip_ = buf;
+      this->publish_state(buf);
     }
   }
   float get_setup_priority() const override { return setup_priority::AFTER_WIFI; }
@@ -89,7 +88,9 @@ class ExtAddrOpenThreadInfo : public OpenThreadInstancePollingComponent, public
     const auto *extaddr = otLinkGetExtendedAddress(instance);
     if (!std::equal(this->last_extaddr_.begin(), this->last_extaddr_.end(), extaddr->m8)) {
       std::copy(extaddr->m8, extaddr->m8 + 8, this->last_extaddr_.begin());
-      this->publish_state(format_hex(extaddr->m8, 8));
+      char buf[format_hex_size(8)];
+      format_hex_to(buf, extaddr->m8, 8);
+      this->publish_state(buf);
     }
   }
   float get_setup_priority() const override { return setup_priority::AFTER_WIFI; }
@@ -107,7 +108,9 @@ class Eui64OpenThreadInfo : public OpenThreadInstancePollingComponent, public te
 
     if (!std::equal(this->last_eui64_.begin(), this->last_eui64_.end(), addr.m8)) {
       std::copy(addr.m8, addr.m8 + 8, this->last_eui64_.begin());
-      this->publish_state(format_hex(this->last_eui64_.begin(), 8));
+      char buf[format_hex_size(8)];
+      format_hex_to(buf, this->last_eui64_.data(), 8);
+      this->publish_state(buf);
     }
   }
   float get_setup_priority() const override { return setup_priority::AFTER_WIFI; }
@@ -123,7 +126,9 @@ class ChannelOpenThreadInfo : public OpenThreadInstancePollingComponent, public
     uint8_t channel = otLinkGetChannel(instance);
     if (this->last_channel_ != channel) {
       this->last_channel_ = channel;
-      this->publish_state(std::to_string(this->last_channel_));
+      char buf[4];  // max "255" + null
+      snprintf(buf, sizeof(buf), "%u", channel);
+      this->publish_state(buf);
     }
   }
   float get_setup_priority() const override { return setup_priority::AFTER_WIFI; }
@@ -168,7 +173,9 @@ class NetworkKeyOpenThreadInfo : public DatasetOpenThreadInfo, public text_senso
   void update_dataset(otOperationalDataset *dataset) override {
     if (!std::equal(this->last_key_.begin(), this->last_key_.end(), dataset->mNetworkKey.m8)) {
       std::copy(dataset->mNetworkKey.m8, dataset->mNetworkKey.m8 + 16, this->last_key_.begin());
-      this->publish_state(format_hex(dataset->mNetworkKey.m8, 16));
+      char buf[format_hex_size(16)];
+      format_hex_to(buf, dataset->mNetworkKey.m8, 16);
+      this->publish_state(buf);
     }
   }
   float get_setup_priority() const override { return setup_priority::AFTER_WIFI; }
@@ -201,7 +208,9 @@ class ExtPanIdOpenThreadInfo : public DatasetOpenThreadInfo, public text_sensor:
   void update_dataset(otOperationalDataset *dataset) override {
     if (!std::equal(this->last_extpanid_.begin(), this->last_extpanid_.end(), dataset->mExtendedPanId.m8)) {
       std::copy(dataset->mExtendedPanId.m8, dataset->mExtendedPanId.m8 + 8, this->last_extpanid_.begin());
-      this->publish_state(format_hex(this->last_extpanid_.begin(), 8));
+      char buf[format_hex_size(8)];
+      format_hex_to(buf, this->last_extpanid_.data(), 8);
+      this->publish_state(buf);
     }
   }