diff --git a/tests/benchmarks/components/api/bench_proto_decode.cpp b/tests/benchmarks/components/api/bench_proto_decode.cpp
index a5ecf78cde3..113201dd8a1 100644
--- a/tests/benchmarks/components/api/bench_proto_decode.cpp
+++ b/tests/benchmarks/components/api/bench_proto_decode.cpp
@@ -10,24 +10,32 @@ namespace esphome::api::benchmarks {
 // sub-microsecond benchmarks.
 static constexpr int kInnerIterations = 2000;
 
+// Helper: encode a message into a buffer and return it.
+// Benchmarks encode once in setup, then decode the resulting bytes in a loop.
+// This keeps decode benchmarks in sync with the actual protobuf schema —
+// hand-encoded byte arrays would silently break when fields change.
+template<typename T> static APIBuffer encode_message(const T &msg) {
+  APIBuffer buffer;
+  uint32_t size = msg.calculate_size();
+  buffer.resize(size);
+  ProtoWriteBuffer writer(&buffer, 0);
+  msg.encode(writer);
+  return buffer;
+}
+
 // --- HelloRequest decode (string + varint fields) ---
 
 static void Decode_HelloRequest(benchmark::State &state) {
-  // Manually encoded HelloRequest:
-  // field 1 (string): "aioesphomeapi"
-  // field 2 (varint): 1  (api_version_major)
-  // field 3 (varint): 10 (api_version_minor)
-  uint8_t encoded[] = {
-      0x0A, 0x0D,                                                         // field 1, length 13
-      'a',  'i',  'o', 'e', 's', 'p', 'h', 'o', 'm', 'e', 'a', 'p', 'i',  // "aioesphomeapi"
-      0x10, 0x01,                                                         // field 2, value 1
-      0x18, 0x0A,                                                         // field 3, value 10
-  };
+  HelloRequest source;
+  source.client_info = StringRef::from_lit("aioesphomeapi");
+  source.api_version_major = 1;
+  source.api_version_minor = 10;
+  auto encoded = encode_message(source);
 
   for (auto _ : state) {
     HelloRequest msg;
     for (int i = 0; i < kInnerIterations; i++) {
-      msg.decode(encoded, sizeof(encoded));
+      msg.decode(encoded.data(), encoded.size());
     }
     benchmark::DoNotOptimize(msg.api_version_major);
   }
@@ -38,17 +46,15 @@ BENCHMARK(Decode_HelloRequest);
 // --- SwitchCommandRequest decode (simple command) ---
 
 static void Decode_SwitchCommandRequest(benchmark::State &state) {
-  // field 1 (fixed32): key = 0x12345678
-  // field 2 (varint): state = true
-  uint8_t encoded[] = {
-      0x0D, 0x78, 0x56, 0x34, 0x12,  // field 1, fixed32
-      0x10, 0x01,                    // field 2, varint true
-  };
+  SwitchCommandRequest source;
+  source.key = 0x12345678;
+  source.state = true;
+  auto encoded = encode_message(source);
 
   for (auto _ : state) {
     SwitchCommandRequest msg;
     for (int i = 0; i < kInnerIterations; i++) {
-      msg.decode(encoded, sizeof(encoded));
+      msg.decode(encoded.data(), encoded.size());
     }
     benchmark::DoNotOptimize(msg.state);
   }
@@ -59,70 +65,24 @@ BENCHMARK(Decode_SwitchCommandRequest);
 // --- LightCommandRequest decode (complex command with many fields) ---
 
 static void Decode_LightCommandRequest(benchmark::State &state) {
-  uint8_t encoded[] = {
-      // field 1: key (fixed32) = 0x11223344
-      0x0D,
-      0x44,
-      0x33,
-      0x22,
-      0x11,
-      // field 2: has_state (varint) = true
-      0x10,
-      0x01,
-      // field 3: state (varint) = true
-      0x18,
-      0x01,
-      // field 4: has_brightness (varint) = true
-      0x20,
-      0x01,
-      // field 5: brightness (fixed32/float) = 0.8
-      0x2D,
-      0xCD,
-      0xCC,
-      0x4C,
-      0x3F,
-      // field 9: has_rgb (varint) = true
-      0x48,
-      0x01,
-      // field 10: red (fixed32/float) = 1.0
-      0x55,
-      0x00,
-      0x00,
-      0x80,
-      0x3F,
-      // field 11: green (fixed32/float) = 0.5
-      0x5D,
-      0x00,
-      0x00,
-      0x00,
-      0x3F,
-      // field 12: blue (fixed32/float) = 0.2
-      0x65,
-      0xCD,
-      0xCC,
-      0x4C,
-      0x3E,
-      // field 20: has_effect (varint) = true
-      0xA0,
-      0x01,
-      0x01,
-      // field 21: effect (string) = "rainbow"
-      0xAA,
-      0x01,
-      0x07,
-      'r',
-      'a',
-      'i',
-      'n',
-      'b',
-      'o',
-      'w',
-  };
+  LightCommandRequest source;
+  source.key = 0x11223344;
+  source.has_state = true;
+  source.state = true;
+  source.has_brightness = true;
+  source.brightness = 0.8f;
+  source.has_rgb = true;
+  source.red = 1.0f;
+  source.green = 0.5f;
+  source.blue = 0.2f;
+  source.has_effect = true;
+  source.effect = StringRef::from_lit("rainbow");
+  auto encoded = encode_message(source);
 
   for (auto _ : state) {
     LightCommandRequest msg;
     for (int i = 0; i < kInnerIterations; i++) {
-      msg.decode(encoded, sizeof(encoded));
+      msg.decode(encoded.data(), encoded.size());
     }
     benchmark::DoNotOptimize(msg.brightness);
   }