Grok TTS
Summary
Grok TTS is a proprietary speech model from xAI, released on 16 Mar 2026. It accepts text and generates audio, with a 15K-token context window and up to 15K output tokens per response.
Convert text into spoken audio with a single API call. The API supports a rich set of expressive voices, inline speech tags for fine-grained delivery control, and output formats from high-fidelity MP3 to telephony-optimized μ-law.
Last verified 21 Oct 2026. Every figure on this page links to its source.
Specifications
| Developer | xAI |
|---|---|
| Release date | 16 Mar 2026 [models.dev] |
| Status | Generally available [models.dev] |
| Weights | Proprietary (API only) [models.dev] |
| Context window | 15K (15,000 tokens) [models.dev] |
| Max output | 15K tokens [models.dev] |
| Input | Text [models.dev] |
| Output | Audio [models.dev] |
| Reasoning mode | No [models.dev] |
| Tool calling | No [models.dev] |
Grok TTS API pricing by provider
USD per million tokens. Sorted by input price.
| Provider | Input | Output | Cached input | Context | Source |
|---|---|---|---|---|---|
| Vercel AI Gateway spacexai/grok-tts | – | – | – | 15K | models.dev, 21 Oct 2026 |
Frequently asked questions
What is the context window of Grok TTS?
Grok TTS has a context window of 15,000 tokens (15K) and can generate up to 15,000 tokens in a single response, according to models.dev.
Is Grok TTS open source?
No. Grok TTS is a proprietary model; xAI has not released its weights. It is available through APIs including Vercel AI Gateway.
When was Grok TTS released?
xAI released Grok TTS on 16 Mar 2026, according to models.dev.
Change history
- Added to the directory
- Now listed on Vercel AI Gateway