diff --git a/esphome/components/sun_gtil2/sun_gtil2.cpp b/esphome/components/sun_gtil2/sun_gtil2.cpp
index 46b4902654..d416d9a636 100644
--- a/esphome/components/sun_gtil2/sun_gtil2.cpp
+++ b/esphome/components/sun_gtil2/sun_gtil2.cpp
@@ -47,14 +47,15 @@ void SunGTIL2::loop() {
   }
 }
 
-std::string SunGTIL2::state_to_string_(uint8_t state) {
+const char *SunGTIL2::state_to_string_(uint8_t state, std::span<char, STATE_BUFFER_SIZE> buffer) {
   switch (state) {
     case 0x02:
       return "Starting voltage too low";
     case 0x07:
       return "Working";
     default:
-      return str_sprintf("Unknown (0x%02x)", state);
+      snprintf(buffer.data(), buffer.size(), "Unknown (0x%02x)", state);
+      return buffer.data();
   }
 }
 
@@ -106,12 +107,11 @@ void SunGTIL2::handle_char_(uint8_t c) {
 #endif
 #ifdef USE_TEXT_SENSOR
   if (this->state_ != nullptr) {
-    this->state_->publish_state(this->state_to_string_(msg.state));
+    char state_buffer[STATE_BUFFER_SIZE];
+    this->state_->publish_state(this->state_to_string_(msg.state, state_buffer));
   }
   if (this->serial_number_ != nullptr) {
-    std::string serial_number;
-    serial_number.assign(msg.serial_number, 10);
-    this->serial_number_->publish_state(serial_number);
+    this->serial_number_->publish_state(msg.serial_number, 10);
   }
 #endif
 }
diff --git a/esphome/components/sun_gtil2/sun_gtil2.h b/esphome/components/sun_gtil2/sun_gtil2.h
index 0c29ae695d..ebdd2abe5b 100644
--- a/esphome/components/sun_gtil2/sun_gtil2.h
+++ b/esphome/components/sun_gtil2/sun_gtil2.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <span>
+
 #include "esphome/core/component.h"
 #include "esphome/core/defines.h"
 
@@ -34,8 +36,10 @@ class SunGTIL2 : public Component, public uart::UARTDevice {
   void set_serial_number(text_sensor::TextSensor *text_sensor) { serial_number_ = text_sensor; }
 #endif
 
+  static constexpr size_t STATE_BUFFER_SIZE = 16;
+
  protected:
-  std::string state_to_string_(uint8_t state);
+  const char *state_to_string_(uint8_t state, std::span<char, STATE_BUFFER_SIZE> buffer);
 #ifdef USE_SENSOR
   sensor::Sensor *ac_voltage_{nullptr};
   sensor::Sensor *dc_voltage_{nullptr};
diff --git a/esphome/components/text/text.cpp b/esphome/components/text/text.cpp
index 3824c5004d..c2ade56f69 100644
--- a/esphome/components/text/text.cpp
+++ b/esphome/components/text/text.cpp
@@ -15,7 +15,10 @@ void Text::publish_state(const char *state) { this->publish_state(state, strlen(
 
 void Text::publish_state(const char *state, size_t len) {
   this->set_has_state(true);
-  this->state.assign(state, len);
+  // Only assign if changed to avoid heap allocation
+  if (len != this->state.size() || memcmp(state, this->state.data(), len) != 0) {
+    this->state.assign(state, len);
+  }
   if (this->traits.get_mode() == TEXT_MODE_PASSWORD) {
     ESP_LOGD(TAG, "'%s': Sending state " LOG_SECRET("'%s'"), this->get_name().c_str(), this->state.c_str());
   } else {
diff --git a/esphome/components/text_sensor/text_sensor.cpp b/esphome/components/text_sensor/text_sensor.cpp
index 174a98054f..66301564a4 100644
--- a/esphome/components/text_sensor/text_sensor.cpp
+++ b/esphome/components/text_sensor/text_sensor.cpp
@@ -32,7 +32,10 @@ void TextSensor::publish_state(const char *state) { this->publish_state(state, s
 void TextSensor::publish_state(const char *state, size_t len) {
   if (this->filter_list_ == nullptr) {
     // No filters: raw_state == state, store once and use for both callbacks
-    this->state.assign(state, len);
+    // Only assign if changed to avoid heap allocation
+    if (len != this->state.size() || memcmp(state, this->state.data(), len) != 0) {
+      this->state.assign(state, len);
+    }
     this->raw_callback_.call(this->state);
     ESP_LOGV(TAG, "'%s': Received new state %s", this->name_.c_str(), this->state.c_str());
     this->notify_frontend_();
@@ -40,7 +43,10 @@ void TextSensor::publish_state(const char *state, size_t len) {
     // Has filters: need separate raw storage
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-    this->raw_state.assign(state, len);
+    // Only assign if changed to avoid heap allocation
+    if (len != this->raw_state.size() || memcmp(state, this->raw_state.data(), len) != 0) {
+      this->raw_state.assign(state, len);
+    }
     this->raw_callback_.call(this->raw_state);
     ESP_LOGV(TAG, "'%s': Received new state %s", this->name_.c_str(), this->raw_state.c_str());
     this->filter_list_->input(this->raw_state);
@@ -101,7 +107,10 @@ void TextSensor::internal_send_state_to_frontend(const std::string &state) {
 }
 
 void TextSensor::internal_send_state_to_frontend(const char *state, size_t len) {
-  this->state.assign(state, len);
+  // Only assign if changed to avoid heap allocation
+  if (len != this->state.size() || memcmp(state, this->state.data(), len) != 0) {
+    this->state.assign(state, len);
+  }
   this->notify_frontend_();
 }