Grok Voice API pricing and setup
Grok Voice (grok-voice) is a xAI model. It is available through the relay.fast API with one relay.fast key and pay-as-you-go billing.
Prices checked from the live catalog. "From" is the lowest price among the relay.fast sources that currently serve the model. The price you pay depends on the source your request uses and can change on any day. The pricing page always shows current values.
| List price | $0.032 per request |
|---|---|
| relay.fast price from | $0.032 per request |
| Endpoints | /v1/audio/speech |
Example request
Keep the key in the RELAY_FAST_API_KEY environment variable. The voices of this model are listed in the live catalog.
curl https://relay.fast/v1/audio/speech \
-H "Authorization: Bearer $RELAY_FAST_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model":"grok-voice","input":"Hello!","voice":"VOICE"}' \
--output speech.mp3Frequently asked questions
How much does the Grok Voice API cost?
On 2026-11-05, Grok Voice costs from $0.032 per request on relay.fast, against a list price of $0.032. The price depends on the source your request uses and can change; https://relay.fast/pricing/grok-voice shows the current value.
Which API endpoint does Grok Voice use?
Call /v1/audio/speech with a relay.fast API key. OpenAI-compatible SDKs use the base URL https://relay.fast/v1.
Do I need a xAI account to use Grok Voice?
No. You use a relay.fast account and API key. relay.fast is an independent API gateway and is not affiliated with xAI.