diff --git a/esphome/components/api/proto.h b/esphome/components/api/proto.h
index 4c6d2fc495..7c472fb5d4 100644
--- a/esphome/components/api/proto.h
+++ b/esphome/components/api/proto.h
@@ -220,10 +220,6 @@ class ProtoWriteBuffer {
   ProtoWriteBuffer(std::vector<uint8_t> *buffer) : buffer_(buffer), pos_(buffer->data() + buffer->size()) {}
   ProtoWriteBuffer(std::vector<uint8_t> *buffer, size_t write_pos)
       : buffer_(buffer), pos_(buffer->data() + write_pos) {}
-  void write(uint8_t value) {
-    this->debug_check_bounds_(1);
-    *this->pos_++ = value;
-  }
   void encode_varint_raw(uint32_t value) {
     while (value > 0x7F) {
       this->debug_check_bounds_(1);
@@ -254,10 +250,7 @@ class ProtoWriteBuffer {
    *
    * Following https://protobuf.dev/programming-guides/encoding/#structure
    */
-  void encode_field_raw(uint32_t field_id, uint32_t type) {
-    uint32_t val = (field_id << 3) | (type & WIRE_TYPE_MASK);
-    this->encode_varint_raw(val);
-  }
+  void encode_field_raw(uint32_t field_id, uint32_t type) { this->encode_varint_raw((field_id << 3) | type); }
   void encode_string(uint32_t field_id, const char *string, size_t len, bool force = false) {
     if (len == 0 && !force)
       return;
@@ -303,10 +296,17 @@ class ProtoWriteBuffer {
       return;
 
     this->encode_field_raw(field_id, 5);  // type 5: 32-bit fixed32
-    this->write((value >> 0) & 0xFF);
-    this->write((value >> 8) & 0xFF);
-    this->write((value >> 16) & 0xFF);
-    this->write((value >> 24) & 0xFF);
+    this->debug_check_bounds_(4);
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+    // Protobuf fixed32 is little-endian, so direct copy works
+    std::memcpy(this->pos_, &value, 4);
+    this->pos_ += 4;
+#else
+    *this->pos_++ = (value >> 0) & 0xFF;
+    *this->pos_++ = (value >> 8) & 0xFF;
+    *this->pos_++ = (value >> 16) & 0xFF;
+    *this->pos_++ = (value >> 24) & 0xFF;
+#endif
   }
   // NOTE: Wire type 1 (64-bit fixed: double, fixed64, sfixed64) is intentionally
   // not supported to reduce overhead on embedded systems. All ESPHome devices are
@@ -936,6 +936,7 @@ inline void ProtoWriteBuffer::encode_message(uint32_t field_id, const ProtoMessa
   // The copy writes msg_length_bytes bytes starting from our current pos_.
   // We then advance our pos_ by the known message size.
   value.encode(*this);
+  this->debug_check_bounds_(msg_length_bytes);
   this->pos_ += msg_length_bytes;
 }