As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/m/grok-tts/

# Grok Text to Speech (Grok TTS API)

xAI, Grok Voice family. Status: current. Type: speech and audio. Released: 2026-04-17.

## How to call it

| Provider | Model id | Endpoint | Docs |
|---|---|---|---|
| xAI API (REST) |  | https://api.x.ai/v1/tts | https://docs.x.ai/developers/model-capabilities/audio/text-to-speech |
| xAI API (WebSocket streaming) |  | wss://api.x.ai/v1/tts | https://docs.x.ai/developers/model-capabilities/audio/text-to-speech |

## Pricing

- Per 1M characters: $15
- Unit as published: USD per 1M characters
- Source: https://docs.x.ai/developers/pricing
- Last checked: 2026-09-29

## Specs

- Input: text
- Output: audio
- Context window: not published
- Max output: not published
- Open weights: no
- Licence: proprietary

## Where it stands

- Newer speech and audio models in the registry since its release: 60. The 5 newest:
  - NVIDIA Nemotron 3.5 Transcribe (30B-A4B) (2026-10-28) https://postcutoff.com/m/nemotron-3-5-transcribe/
  - Hy-SimulMT-30B-A3B (2026-10-22) https://postcutoff.com/m/hy-simulmt-30b-a3b/
  - Eleven Realtime v1 Max / Mini (2026-10-20) https://postcutoff.com/m/eleven-realtime-v1-max/
  - Voxtral Mini Transcribe 3 (+ Mini Transcribe Realtime 3) (2026-10-20) https://postcutoff.com/m/voxtral-mini-transcribe-3/
  - Voxtral Small Transcribe 3 (2026-10-20) https://postcutoff.com/m/voxtral-small-transcribe-3/
- After it from xAI: Grok Voice Think Fast 2.0 (2026-07-29) https://postcutoff.com/m/grok-voice-think-fast-2-0/
- Closed weights; access is hosted only.

## What stands out

- Inline speech tags: Inline tags ([pause], [laugh], [sigh], [cry], [gasp], ...) and wrapping tags (<whisper>, <soft>, <loud>, <slow>, <fast>, <sing>) control delivery. Source: https://docs.x.ai/developers/model-capabilities/audio/text-to-speech
- Custom (cloned) voices (found after launch): Clone a voice from a short reference clip via the Custom Voices API; the voice_id works like built-in voices in TTS and the Voice Agent API. Source: https://docs.x.ai/developers/model-capabilities/audio/text-to-speech

## Notes

Launched with the Grok STT API on 2026-04-17 (some press reports an earlier developer opening in March 2026). No separate model id is documented; the endpoint selects the model. 60,000 characters per REST request; ~20 languages plus auto-detect; MP3/WAV/PCM/mu-law/A-law at 8-48 kHz; voice list via GET /v1/tts/voices (Ara, Eve, Leo, Rex, Sal and many more).

Call `POST https://api.x.ai/v1/tts` with your text and a `voice` (see the docs for the exact request schema).

Sources: https://docs.x.ai/developers/model-capabilities/audio/text-to-speech · https://x.ai/news/grok-stt-and-tts-apis · https://docs.x.ai/developers/pricing

Model page: https://postcutoff.com/m/grok-tts/