Beta xAI

xAI Grok TTS

Beta text-to-speech API from xAI with streaming and batch output in MP3/WAV/PCM/mu-law/A-law. Price shown as beta pricing; WebSocket text streaming is used by integrations such as Pipecat.

Est. per minute$0.0038 - 0.013

1 high-severity warning

Overview

Best for: Experimenting if you already use Grok models; verify pricing first.

At a glance

Text stream inYes

8 kHz phoneYes

Concurrency10

WebRTCNo

WebSocketYes

gRPCNo

EU dataNo

Self-hostNo

Open weightsNo

Beta. Price unconfirmed: $4.20/1M (docs snippet) vs $15/1M (OpenRouter). Vapi measured 285 ms median incl. network; no vendor figure. Concurrency 10 per team from secondary sources. us-east-1 only. Text streaming per the Pipecat integration.

Audio in

Text

Audio out

MP3, WAV, PCM, mu-law, A-law

Languages

Not verified

Voices

Built-in expressive voices; count not verified

Latency

Vapi measured 285 ms median for the streaming variant (June 2026, includes network).

Regions

us-east-1

Compliance

Not verified.

Features

streaming output
WebSocket text streaming with text.clear for barge-in (per Pipecat integration)

Pricing

What	Price	Unit	Notes
Grok TTS	$4.20 (beta, per search snippet of docs) or $15 (OpenRouter and launch coverage)	per 1M characters	The docs page rendered with blank price cells when fetched

How the per-minute estimate was worked out

900 chars/min at $4.20/1M (beta) vs $15/1M; unverified which applies

Free tier: Not verified

Source: docs.x.ai

Setup

Create an xAI API key.
See docs.x.ai voice/TTS reference for the REST and WebSocket endpoints.

Endpoint

See https://docs.x.ai/developers/models/text-to-speech

Authentication

Authorization: Bearer <XAI_API_KEY>

Warnings

Beta pricing and limits may change

xAI marks TTS as beta; price and rate limits may change at GA, and sources disagree on the current rate ($4.20 vs $15 per 1M).

Low concurrency reported

Secondary sources cite 10 concurrent requests per team, which is tight for production agents.

Single US region

Cluster listed as us-east-1 only; expect higher latency from Europe/Asia.

Plus 12 warnings that apply to all text-to-speech, streaming APIs. See category warnings.

Limits

Reported: 15,000 characters per REST request; 600 RPM and 10 concurrent requests per team (secondary sources)

Models and products

Name	Status	Notes
Grok TTS (model ID not shown on the docs page fetched)	Beta	OpenRouter lists 'grok-voice-tts-1.0'.

Docs and sources

Docs

Sources used

Not fully verified

Price, model ID, WebSocket URL and message schema, voices and languages.

Similar text-to-speech APIs

SpeechifySpeechifyAI (Simba 3.2 / 3.0)$0.0054 - 0.009/min0 high-severity warnings Inworld AIInworld TTS (Realtime TTS-2, TTS-2 Flash)$0.0063 - 0.022/min0 high-severity warnings Unreal SpeechUnreal Speech$0.0072 - 0.015/min0 high-severity warnings Google CloudGoogle Cloud Text-to-Speech (Chirp 3 HD and Gemini-TTS)$0.009 - 0.03/min2 high-severity warnings

Spotted a wrong price or a dead link?