diff --git a/esphome/components/api/__init__.py b/esphome/components/api/__init__.py
index 47ed036658..a684439bf9 100644
--- a/esphome/components/api/__init__.py
+++ b/esphome/components/api/__init__.py
@@ -356,6 +356,7 @@ async def homeassistant_service_to_code(
         cg.add(var.set_response_template(templ))
 
     if on_response := config.get(CONF_ON_RESPONSE):
+        cg.add_define("USE_API_HOMEASSISTANT_ACTION_RESPONSES")
         trigger = cg.new_Pvariable(
             on_response[CONF_TRIGGER_ID],
             template_arg,
diff --git a/esphome/components/api/api.proto b/esphome/components/api/api.proto
index b37344f566..988d651304 100644
--- a/esphome/components/api/api.proto
+++ b/esphome/components/api/api.proto
@@ -789,12 +789,12 @@ message HomeassistantActionResponse {
   option (id) = 130;
   option (source) = SOURCE_CLIENT;
   option (no_delay) = true;
-  option (ifdef) = "USE_API_HOMEASSISTANT_SERVICES";
+  option (ifdef) = "USE_API_HOMEASSISTANT_ACTION_RESPONSES";
 
   uint32 call_id = 1; // Matches the call_id from HomeassistantActionRequest
   bool success = 2; // Whether the service call succeeded
   string error_message = 3; // Error message if success = false
-  string response_data = 4; // Service response data
+  bytes response_data = 4 [(pointer_to_buffer) = true]; // Service response data
 }
 
 // ==================== IMPORT HOME ASSISTANT STATES ====================
diff --git a/esphome/components/api/api_connection.cpp b/esphome/components/api/api_connection.cpp
index 9d76adf98e..5a840898cc 100644
--- a/esphome/components/api/api_connection.cpp
+++ b/esphome/components/api/api_connection.cpp
@@ -1550,9 +1550,10 @@ void APIConnection::execute_service(const ExecuteServiceRequest &msg) {
 }
 #endif
 
-#ifdef USE_API_HOMEASSISTANT_SERVICES
+#if defined(USE_API_HOMEASSISTANT_SERVICES) && defined(USE_API_HOMEASSISTANT_ACTION_RESPONSES)
 void APIConnection::on_homeassistant_action_response(const HomeassistantActionResponse &msg) {
-  this->parent_->handle_action_response(msg.call_id, msg.success, msg.error_message, msg.response_data);
+  this->parent_->handle_action_response(msg.call_id, msg.success, msg.error_message,
+                                        reinterpret_cast<const char *>(msg.response_data), msg.response_data_len);
 };
 #endif
 #ifdef USE_API_NOISE
diff --git a/esphome/components/api/api_connection.h b/esphome/components/api/api_connection.h
index 401fef28dc..b7938dbce3 100644
--- a/esphome/components/api/api_connection.h
+++ b/esphome/components/api/api_connection.h
@@ -137,8 +137,10 @@ class APIConnection final : public APIServerConnection {
       return;
     this->send_message(call, HomeassistantActionRequest::MESSAGE_TYPE);
   }
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
   void on_homeassistant_action_response(const HomeassistantActionResponse &msg) override;
 #endif
+#endif
 #ifdef USE_BLUETOOTH_PROXY
   void subscribe_bluetooth_le_advertisements(const SubscribeBluetoothLEAdvertisementsRequest &msg) override;
   void unsubscribe_bluetooth_le_advertisements(const UnsubscribeBluetoothLEAdvertisementsRequest &msg) override;
diff --git a/esphome/components/api/api_pb2.cpp b/esphome/components/api/api_pb2.cpp
index 210b6505ce..00282d4294 100644
--- a/esphome/components/api/api_pb2.cpp
+++ b/esphome/components/api/api_pb2.cpp
@@ -896,6 +896,8 @@ void HomeassistantActionRequest::calculate_size(ProtoSize &size) const {
   size.add_uint32(1, this->call_id);
   size.add_length(1, this->response_template.size());
 }
+#endif
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
 bool HomeassistantActionResponse::decode_varint(uint32_t field_id, ProtoVarInt value) {
   switch (field_id) {
     case 1:
@@ -914,9 +916,12 @@ bool HomeassistantActionResponse::decode_length(uint32_t field_id, ProtoLengthDe
     case 3:
       this->error_message = value.as_string();
       break;
-    case 4:
-      this->response_data = value.as_string();
+    case 4: {
+      // Use raw data directly to avoid allocation
+      this->response_data = value.data();
+      this->response_data_len = value.size();
       break;
+    }
     default:
       return false;
   }
diff --git a/esphome/components/api/api_pb2.h b/esphome/components/api/api_pb2.h
index aa5ef155ea..9e03976f03 100644
--- a/esphome/components/api/api_pb2.h
+++ b/esphome/components/api/api_pb2.h
@@ -1124,17 +1124,20 @@ class HomeassistantActionRequest final : public ProtoMessage {
 
  protected:
 };
+#endif
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
 class HomeassistantActionResponse final : public ProtoDecodableMessage {
  public:
   static constexpr uint8_t MESSAGE_TYPE = 130;
-  static constexpr uint8_t ESTIMATED_SIZE = 24;
+  static constexpr uint8_t ESTIMATED_SIZE = 34;
 #ifdef HAS_PROTO_MESSAGE_DUMP
   const char *message_name() const override { return "homeassistant_action_response"; }
 #endif
   uint32_t call_id{0};
   bool success{false};
   std::string error_message{};
-  std::string response_data{};
+  const uint8_t *response_data{nullptr};
+  uint16_t response_data_len{0};
 #ifdef HAS_PROTO_MESSAGE_DUMP
   void dump_to(std::string &out) const override;
 #endif
diff --git a/esphome/components/api/api_pb2_dump.cpp b/esphome/components/api/api_pb2_dump.cpp
index 9b655cc1a2..1f3073519b 100644
--- a/esphome/components/api/api_pb2_dump.cpp
+++ b/esphome/components/api/api_pb2_dump.cpp
@@ -1125,12 +1125,16 @@ void HomeassistantActionRequest::dump_to(std::string &out) const {
   dump_field(out, "call_id", this->call_id);
   dump_field(out, "response_template", this->response_template);
 }
+#endif
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
 void HomeassistantActionResponse::dump_to(std::string &out) const {
   MessageDumpHelper helper(out, "HomeassistantActionResponse");
   dump_field(out, "call_id", this->call_id);
   dump_field(out, "success", this->success);
   dump_field(out, "error_message", this->error_message);
-  dump_field(out, "response_data", this->response_data);
+  out.append("  response_data: ");
+  out.append(format_hex_pretty(this->response_data, this->response_data_len));
+  out.append("\n");
 }
 #endif
 #ifdef USE_API_HOMEASSISTANT_STATES
diff --git a/esphome/components/api/api_pb2_service.cpp b/esphome/components/api/api_pb2_service.cpp
index 6f596a2edc..9d227af0a3 100644
--- a/esphome/components/api/api_pb2_service.cpp
+++ b/esphome/components/api/api_pb2_service.cpp
@@ -611,7 +611,7 @@ void APIServerConnectionBase::read_message(uint32_t msg_size, uint32_t msg_type,
       break;
     }
 #endif
-#ifdef USE_API_HOMEASSISTANT_SERVICES
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
     case HomeassistantActionResponse::MESSAGE_TYPE: {
       HomeassistantActionResponse msg;
       msg.decode(msg_data, msg_size);
diff --git a/esphome/components/api/api_pb2_service.h b/esphome/components/api/api_pb2_service.h
index f3f39d48ec..549b00ee6a 100644
--- a/esphome/components/api/api_pb2_service.h
+++ b/esphome/components/api/api_pb2_service.h
@@ -66,7 +66,7 @@ class APIServerConnectionBase : public ProtoService {
   virtual void on_subscribe_homeassistant_services_request(const SubscribeHomeassistantServicesRequest &value){};
 #endif
 
-#ifdef USE_API_HOMEASSISTANT_SERVICES
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
   virtual void on_homeassistant_action_response(const HomeassistantActionResponse &value){};
 #endif
 #ifdef USE_API_HOMEASSISTANT_STATES
diff --git a/esphome/components/api/api_server.cpp b/esphome/components/api/api_server.cpp
index d21658c940..76d5e4d9a7 100644
--- a/esphome/components/api/api_server.cpp
+++ b/esphome/components/api/api_server.cpp
@@ -404,17 +404,17 @@ void APIServer::send_homeassistant_action(const HomeassistantActionRequest &call
   }
 }
 
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
 void APIServer::register_action_response_callback(uint32_t call_id, ActionResponseCallback callback) {
   this->action_response_callbacks_[call_id] = std::move(callback);
 }
 
 void APIServer::handle_action_response(uint32_t call_id, bool success, const std::string &error_message,
-                                       const std::string &response_data) {
+                                       const char *response_data, size_t response_data_len) {
   auto it = this->action_response_callbacks_.find(call_id);
   if (it != this->action_response_callbacks_.end()) {
     // Create the response object
-    auto response = std::make_shared<class ActionResponse>(success, error_message);
-    response->set_data(response_data);
+    auto response = std::make_shared<class ActionResponse>(success, error_message, response_data, response_data_len);
 
     // Call the callback
     it->second(response);
@@ -424,6 +424,7 @@ void APIServer::handle_action_response(uint32_t call_id, bool success, const std
   }
 }
 #endif
+#endif
 
 #ifdef USE_API_HOMEASSISTANT_STATES
 void APIServer::subscribe_home_assistant_state(std::string entity_id, optional<std::string> attribute,
diff --git a/esphome/components/api/api_server.h b/esphome/components/api/api_server.h
index b346d83ac8..24b4bf4cf9 100644
--- a/esphome/components/api/api_server.h
+++ b/esphome/components/api/api_server.h
@@ -111,12 +111,13 @@ class APIServer : public Component, public Controller {
 #endif
 #ifdef USE_API_HOMEASSISTANT_SERVICES
   void send_homeassistant_action(const HomeassistantActionRequest &call);
-
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
   // Action response handling
   using ActionResponseCallback = std::function<void(std::shared_ptr<class ActionResponse>)>;
   void register_action_response_callback(uint32_t call_id, ActionResponseCallback callback);
   void handle_action_response(uint32_t call_id, bool success, const std::string &error_message,
-                              const std::string &response_data);
+                              const char *response_data, size_t response_data_len);
+#endif
 #endif
 #ifdef USE_API_SERVICES
   void register_user_service(UserServiceDescriptor *descriptor) { this->user_services_.push_back(descriptor); }
@@ -193,7 +194,7 @@ class APIServer : public Component, public Controller {
 #ifdef USE_API_SERVICES
   std::vector<UserServiceDescriptor *> user_services_;
 #endif
-#ifdef USE_API_HOMEASSISTANT_SERVICES
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
   std::map<uint32_t, ActionResponseCallback> action_response_callbacks_;
 #endif
 
diff --git a/esphome/components/api/homeassistant_service.h b/esphome/components/api/homeassistant_service.h
index 1a1f9c4810..93daf7a90c 100644
--- a/esphome/components/api/homeassistant_service.h
+++ b/esphome/components/api/homeassistant_service.h
@@ -47,35 +47,36 @@ template<typename... Ts> class TemplatableKeyValuePair {
   TemplatableStringValue<Ts...> value;
 };
 
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
 // Represents the response data from a Home Assistant action
 class ActionResponse {
  public:
-  ActionResponse(bool success, std::string error_message = "")
-      : success_(success), error_message_(std::move(error_message)) {}
+  ActionResponse(bool success, std::string error_message, const char *data, size_t data_len)
+      : success_(success), error_message_(std::move(error_message)), data_(data), data_len_(data_len) {}
 
   bool is_success() const { return this->success_; }
   const std::string &get_error_message() const { return this->error_message_; }
-  const std::string &get_data() const { return this->data_; }
+  const char *get_data() const { return this->data_; }
+  size_t get_data_len() const { return this->data_len_; }
   // Get data as parsed JSON object
   // Returns unbound JsonObject if data is empty or invalid JSON
   JsonObject get_json() {
-    if (this->data_.empty())
+    if (this->data_len_ == 0)
       return JsonObject();  // Return unbound JsonObject if no data
 
     if (!this->parsed_json_) {
-      this->json_document_ = json::parse_json(this->data_);
+      this->json_document_ = json::parse_json(this->data_, this->data_len_);
       this->json_ = this->json_document_.as<JsonObject>();
       this->parsed_json_ = true;
     }
     return this->json_;
   }
 
-  void set_data(const std::string &data) { this->data_ = data; }
-
  protected:
   bool success_;
   std::string error_message_;
-  std::string data_;
+  const char *data_;
+  size_t data_len_;
   JsonDocument json_document_;
   JsonObject json_;
   bool parsed_json_{false};
@@ -83,6 +84,7 @@ class ActionResponse {
 
 // Callback type for action responses
 template<typename... Ts> using ActionResponseCallback = std::function<void(std::shared_ptr<ActionResponse>, Ts...)>;
+#endif
 
 template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts...> {
  public:
@@ -101,6 +103,7 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
     this->variables_.emplace_back(std::move(key), value);
   }
 
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
   template<typename T> void set_response_template(T response_template) {
     this->response_template_ = response_template;
     this->has_response_template_ = true;
@@ -110,6 +113,7 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
     this->wants_response_ = true;
     this->response_callback_ = callback;
   }
+#endif
 
   void play(Ts... x) override {
     HomeassistantActionRequest resp;
@@ -135,6 +139,7 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
       kv.value = it.value.value(x...);
     }
 
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
     if (this->wants_response_) {
       // Generate a unique call ID for this service call
       static uint32_t call_id_counter = 1;
@@ -152,6 +157,7 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
         std::apply([this, &response](auto &&...args) { this->response_callback_(response, args...); }, captured_args);
       });
     }
+#endif
 
     this->parent_->send_homeassistant_action(resp);
   }
@@ -163,12 +169,15 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
   std::vector<TemplatableKeyValuePair<Ts...>> data_;
   std::vector<TemplatableKeyValuePair<Ts...>> data_template_;
   std::vector<TemplatableKeyValuePair<Ts...>> variables_;
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
   TemplatableStringValue<Ts...> response_template_{""};
   ActionResponseCallback<Ts...> response_callback_;
   bool wants_response_{false};
   bool has_response_template_{false};
+#endif
 };
 
+#ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
 template<typename... Ts>
 class HomeAssistantActionResponseTrigger : public Trigger<std::shared_ptr<ActionResponse>, Ts...> {
  public:
@@ -177,6 +186,7 @@ class HomeAssistantActionResponseTrigger : public Trigger<std::shared_ptr<Action
         [this](std::shared_ptr<ActionResponse> response, Ts... x) { this->trigger(response, x...); });
   }
 };
+#endif
 
 }  // namespace esphome::api
 #endif
diff --git a/esphome/components/json/json_util.cpp b/esphome/components/json/json_util.cpp
index 643f23f499..d0498b06a5 100644
--- a/esphome/components/json/json_util.cpp
+++ b/esphome/components/json/json_util.cpp
@@ -26,7 +26,7 @@ bool parse_json(const std::string &data, const json_parse_t &f) {
   // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
 }
 
-JsonDocument parse_json(const std::string &data) {
+JsonDocument parse_json(const char *data, size_t len) {
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
 #ifdef USE_PSRAM
   auto doc_allocator = SpiRamAllocator();
@@ -38,12 +38,12 @@ JsonDocument parse_json(const std::string &data) {
     ESP_LOGE(TAG, "Could not allocate memory for JSON document!");
     return JsonObject();  // return unbound object
   }
-  DeserializationError err = deserializeJson(json_document, data);
+  DeserializationError err = deserializeJson(json_document, data, len);
 
   if (err == DeserializationError::Ok) {
     return json_document;
   } else if (err == DeserializationError::NoMemory) {
-    ESP_LOGE(TAG, "Can not allocate more memory for deserialization. Consider making source string smaller");
+    ESP_LOGE(TAG, "Can not allocate more memory for deserialization. Consider making source buffer smaller");
     return JsonObject();  // return unbound object
   }
   ESP_LOGE(TAG, "Parse error: %s", err.c_str());
@@ -51,6 +51,8 @@ JsonDocument parse_json(const std::string &data) {
   // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
 }
 
+JsonDocument parse_json(const std::string &data) { return parse_json(data.c_str(), data.size()); }
+
 std::string JsonBuilder::serialize() {
   if (doc_.overflowed()) {
     ESP_LOGE(TAG, "JSON document overflow");
diff --git a/esphome/components/json/json_util.h b/esphome/components/json/json_util.h
index 0349833342..a3c5cc2f8c 100644
--- a/esphome/components/json/json_util.h
+++ b/esphome/components/json/json_util.h
@@ -51,6 +51,8 @@ std::string build_json(const json_build_t &f);
 bool parse_json(const std::string &data, const json_parse_t &f);
 /// Parse a JSON string and return the root JsonDocument (or an unbound object on error)
 JsonDocument parse_json(const std::string &data);
+/// Parse JSON from a buffer and return the root JsonDocument (or an unbound object on error)
+JsonDocument parse_json(const char *data, size_t len);
 
 /// Builder class for creating JSON documents without lambdas
 class JsonBuilder {
diff --git a/esphome/core/defines.h b/esphome/core/defines.h
index 7fc42ea334..800b0d94d7 100644
--- a/esphome/core/defines.h
+++ b/esphome/core/defines.h
@@ -111,6 +111,7 @@
 #define USE_API_CLIENT_CONNECTED_TRIGGER
 #define USE_API_CLIENT_DISCONNECTED_TRIGGER
 #define USE_API_HOMEASSISTANT_SERVICES
+#define USE_API_HOMEASSISTANT_ACTION_RESPONSES
 #define USE_API_HOMEASSISTANT_STATES
 #define USE_API_NOISE
 #define USE_API_PLAINTEXT