Skip to content

docs(tts): document per-provider max_text_length caps (salvage #13825) #20389

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
teknium1 merged 1 commit into from
May 5, 2026
+37 −0
Merged

docs(tts): document per-provider max_text_length caps (salvage #13825) #20389

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
37 changes: 37 additions & 0 deletions website/docs/user-guide/features/tts.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,43 @@ tts:

**Speed control**: The global `tts.speed` value applies to all providers by default. Each provider can override it with its own `speed` setting (e.g., `tts.openai.speed: 1.5`). Provider-specific speed takes precedence over the global value. Default is `1.0` (normal speed).


### Input length limits

Each provider has a documented per-request input-character cap. Hermes truncates text before calling the provider so requests never fail with a length error:

| Provider | Default cap (chars) |
|----------|---------------------|
| Edge TTS | 5000 |
| OpenAI | 4096 |
| xAI | 15000 |
| MiniMax | 10000 |
| Mistral | 4000 |
| Google Gemini | 5000 |
| ElevenLabs | Model-aware (see below) |
| NeuTTS | 2000 |
| KittenTTS | 2000 |

**ElevenLabs** picks a cap from the configured `model_id`:

| `model_id` | Cap (chars) |
|------------|-------------|
| `eleven_flash_v2_5` | 40000 |
| `eleven_flash_v2` | 30000 |
| `eleven_multilingual_v2` (default), `eleven_multilingual_v1`, `eleven_english_sts_v2`, `eleven_english_sts_v1` | 10000 |
| `eleven_v3`, `eleven_ttv_v3` | 5000 |
| Unknown model | Falls back to provider default (10000) |

**Override per provider** with `max_text_length:` under the provider section of your TTS config:

```yaml
tts:
openai:
max_text_length: 8192 # raise or lower the provider cap
```

Only positive integers are honored. Zero, negative, non-numeric, or boolean values fall through to the provider default, so a broken config can't accidentally disable truncation.

### Telegram Voice Bubbles & ffmpeg

Telegram voice bubbles require Opus/OGG audio format:
Expand Down
Loading