From 6b522dfee6880df49d6826734310ca6ab7f3d25c Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 5 Nov 2025 09:14:21 -0600
Subject: [PATCH 1/3] [wifi_info] Reduce heap usage by up to 1.7KB in
 scan_results sensor (#11723)

---
 esphome/components/wifi_info/wifi_info_text_sensor.h | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/esphome/components/wifi_info/wifi_info_text_sensor.h b/esphome/components/wifi_info/wifi_info_text_sensor.h
index 2cb96123a0..04889d6bb3 100644
--- a/esphome/components/wifi_info/wifi_info_text_sensor.h
+++ b/esphome/components/wifi_info/wifi_info_text_sensor.h
@@ -10,6 +10,8 @@
 namespace esphome {
 namespace wifi_info {
 
+static constexpr size_t MAX_STATE_LENGTH = 255;
+
 class IPAddressWiFiInfo : public PollingComponent, public text_sensor::TextSensor {
  public:
   void update() override {
@@ -71,11 +73,14 @@ class ScanResultsWiFiInfo : public PollingComponent, public text_sensor::TextSen
       scan_results += "dB\n";
     }
 
+    // There's a limit of 255 characters per state.
+    // Longer states just don't get sent so we truncate it.
+    if (scan_results.length() > MAX_STATE_LENGTH) {
+      scan_results.resize(MAX_STATE_LENGTH);
+    }
     if (this->last_scan_results_ != scan_results) {
       this->last_scan_results_ = scan_results;
-      // There's a limit of 255 characters per state.
-      // Longer states just don't get sent so we truncate it.
-      this->publish_state(scan_results.substr(0, 255));
+      this->publish_state(scan_results);
     }
   }
   float get_setup_priority() const override { return setup_priority::AFTER_WIFI; }

From 6e2dbbf636dbe98665904618553caddb0eb46315 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 5 Nov 2025 09:15:05 -0600
Subject: [PATCH 2/3] [voice_assistant] Eliminate substr() allocations in text
 truncation (#11725)

---
 esphome/components/voice_assistant/voice_assistant.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/esphome/components/voice_assistant/voice_assistant.cpp b/esphome/components/voice_assistant/voice_assistant.cpp
index 7ece73994f..fd35dc7d09 100644
--- a/esphome/components/voice_assistant/voice_assistant.cpp
+++ b/esphome/components/voice_assistant/voice_assistant.cpp
@@ -657,7 +657,8 @@ void VoiceAssistant::on_event(const api::VoiceAssistantEventResponse &msg) {
         ESP_LOGW(TAG, "No text in STT_END event");
         return;
       } else if (text.length() > 500) {
-        text = text.substr(0, 497) + "...";
+        text.resize(497);
+        text += "...";
       }
       ESP_LOGD(TAG, "Speech recognised as: \"%s\"", text.c_str());
       this->defer([this, text]() { this->stt_end_trigger_->trigger(text); });
@@ -714,7 +715,8 @@ void VoiceAssistant::on_event(const api::VoiceAssistantEventResponse &msg) {
         return;
       }
       if (text.length() > 500) {
-        text = text.substr(0, 497) + "...";
+        text.resize(497);
+        text += "...";
       }
       ESP_LOGD(TAG, "Response: \"%s\"", text.c_str());
       this->defer([this, text]() {

From 479f8dd85c75b7ca961a7c031330eb5ca4ea41a3 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 5 Nov 2025 09:17:28 -0600
Subject: [PATCH 3/3] [rtttl] Reduce flash usage by eliminating substr()
 allocations (#11722)

---
 esphome/components/rtttl/rtttl.cpp | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/esphome/components/rtttl/rtttl.cpp b/esphome/components/rtttl/rtttl.cpp
index b79f27e2e5..65fcc207d4 100644
--- a/esphome/components/rtttl/rtttl.cpp
+++ b/esphome/components/rtttl/rtttl.cpp
@@ -35,9 +35,9 @@ void Rtttl::dump_config() {
 
 void Rtttl::play(std::string rtttl) {
   if (this->state_ != State::STATE_STOPPED && this->state_ != State::STATE_STOPPING) {
-    int pos = this->rtttl_.find(':');
-    auto name = this->rtttl_.substr(0, pos);
-    ESP_LOGW(TAG, "Already playing: %s", name.c_str());
+    size_t pos = this->rtttl_.find(':');
+    size_t len = (pos != std::string::npos) ? pos : this->rtttl_.length();
+    ESP_LOGW(TAG, "Already playing: %.*s", (int) len, this->rtttl_.c_str());
     return;
   }
 
@@ -59,8 +59,7 @@ void Rtttl::play(std::string rtttl) {
     return;
   }
 
-  auto name = this->rtttl_.substr(0, this->position_);
-  ESP_LOGD(TAG, "Playing song %s", name.c_str());
+  ESP_LOGD(TAG, "Playing song %.*s", (int) this->position_, this->rtttl_.c_str());
 
   // get default duration
   this->position_ = this->rtttl_.find("d=", this->position_);