diff --git a/tests/tools/test_tts_command_providers.py b/tests/tools/test_tts_command_providers.py
index 24c1f25f830be..c096487bc9a76 100644
--- a/tests/tools/test_tts_command_providers.py
+++ b/tests/tools/test_tts_command_providers.py
@@ -243,10 +243,19 @@ class TestConfigGetters:
         assert _get_command_tts_output_format({"format": "ogg"}, "/tmp/clip.xyz") == "ogg"
 
     def test_output_format_rejects_unknown(self):
-        assert _get_command_tts_output_format({"format": "m4a"}) == DEFAULT_COMMAND_TTS_OUTPUT_FORMAT
+        assert _get_command_tts_output_format({"format": "midi"}) == DEFAULT_COMMAND_TTS_OUTPUT_FORMAT
 
     def test_output_format_supported_set(self):
-        assert COMMAND_TTS_OUTPUT_FORMATS == frozenset({"mp3", "wav", "ogg", "flac"})
+        assert COMMAND_TTS_OUTPUT_FORMATS == frozenset(
+            {"mp3", "wav", "ogg", "flac", "m4a", "aac", "amr", "opus"}
+        )
+
+    def test_output_format_accepts_extended_formats(self):
+        # m4a/aac/amr/opus are common ffmpeg-producible containers/codecs;
+        # honored both via explicit config and via the output path suffix.
+        for fmt in ("m4a", "aac", "amr", "opus"):
+            assert _get_command_tts_output_format({"format": fmt}) == fmt
+            assert _get_command_tts_output_format({}, f"/tmp/clip.{fmt}") == fmt
 
     def test_voice_compatible_boolean(self):
         assert _is_command_tts_voice_compatible({"voice_compatible": True}) is True
diff --git a/tools/tts_tool.py b/tools/tts_tool.py
index 92a177fd9bf91..2b9b33109a7c0 100644
--- a/tools/tts_tool.py
+++ b/tools/tts_tool.py
@@ -623,7 +623,9 @@ BUILTIN_TTS_PROVIDERS = frozenset({
 
 DEFAULT_COMMAND_TTS_TIMEOUT_SECONDS = 120
 DEFAULT_COMMAND_TTS_OUTPUT_FORMAT = "mp3"
-COMMAND_TTS_OUTPUT_FORMATS = frozenset({"mp3", "wav", "ogg", "flac"})
+COMMAND_TTS_OUTPUT_FORMATS = frozenset(
+    {"mp3", "wav", "ogg", "flac", "m4a", "aac", "amr", "opus"}
+)
 DEFAULT_COMMAND_TTS_MAX_TEXT_LENGTH = 5000
 
 # Platforms whose native voice-bubble delivery requires Ogg/Opus audio.
diff --git a/website/docs/user-guide/features/tts.md b/website/docs/user-guide/features/tts.md
index 8c15602e6d5fc..6713f77f14a05 100644
--- a/website/docs/user-guide/features/tts.md
+++ b/website/docs/user-guide/features/tts.md
@@ -284,6 +284,8 @@ tts:
       output_format: wav
 ```
 
+**Supported `output_format` values:** `mp3` (default), `wav`, `ogg`, `flac`, `m4a`, `aac`, `amr`, `opus`. Your command must actually produce that format (e.g. via `ffmpeg`); Hermes only validates the declared value and names the output file accordingly. An unknown value falls back to `mp3`. The chosen format is also exposed to the command as the `{format}` placeholder.
+
 #### Example: Doubao (Chinese seed-tts-2.0)
 
 For high-quality Chinese TTS via ByteDance's [seed-tts-2.0](https://www.volcengine.com/docs/6561/1257544) bidirectional-streaming API, install the [`doubao-speech`](https://pypi.org/project/doubao-speech/) PyPI package and wire it in as a command provider: