Grok TTS Review: 71 Preset Voices and Audio Formats
One voice per request, up to 15,000 characters of script.
xAI's Grok text-to-speech, generally available since March 2026: 71 preset voices in 20 languages, laughs, breaths and whispers written straight into the script, and a speed slider. Up to 15,000 characters per request, billed per 1,000 characters, and SpicyAPI adds no content filter.
- Lydia
- Not hands-on tested · catalogue checked Oct 7, 2026
- Updated Oct 7, 2026
The verdict
We did not create new paid samples for this article. Published examples remain examples of a particular input and output, rather than a statistically controlled comparison. The illustration accompanying this article is editorial artwork, not a sample produced by the reviewed model.
What we liked and what held it back
What we liked
- Voice notes and companion apps. Whispered asides, a laugh in the right place, a breath before the next line — written into the script as tags, so the delivery is part of the text you store and replay.
- Multilingual narration. Read the same script in English, Japanese, French, Korean, Arabic and more, either with one of the five multilingual voices or with a native voice for each language.
What held it back
- One voice per request, up to 15,000 characters of script. The result is one audio file; there are no word timings or subtitles. Only the 71 preset voices are offered — no cloning and no custom voices. pcm, mulaw and alaw return raw audio without a file header, which most players and browsers cannot open directly.
What the evidence shows
We have not established a comparable public quality result for this exact served variant in the evidence used by this article. A result for a neighbouring release or a different execution mode would not fill that gap. The controls described here are verified product capabilities; they are not a newly measured naturalness, intelligibility or speed score.
A practical starting brief
The following is a starting input adapted from the model’s published examples, not a promise that every run will sound the same. Keep the words and delivery directions separate wherever the endpoint offers separate fields. Preview an ordinary sentence before extending the script; adding more adjectives rarely resolves an ambiguous instruction.
{
"language": "en",
"text": "Hey, it's me. [pause] I know it's late. [breath] <whisper>I keep thinking about the way you kissed me at the door.</whisper> [giggle] Call me back?",
"voice_id": "eve"
}Start with the material that determines acceptance: a name, a difficult number, a sentence with an emotional turn, or the passage you cannot afford to misread. Listen or read against the original, including the ending. Keep the input fixed while changing one control, so a difference in wording does not get mistaken for a better model. A pleasant voice alone does not prove that every word survived.
Read the current quote on the model task page before submitting. Per-character, per-second and per-request billing cannot be compared by the displayed starting number alone. Compare the same passage or recording, and include any format conversion or alignment you still need to do.
How to choose an alternative
Choose by the missing capability before comparing a headline quality number. An alternative should remove a concrete bottleneck—voice selection, a longer script, delivery direction or the right kind of transcription—rather than simply have a newer name. The current pages below show their actual tasks and price units.
What Grok TTS can do on SpicyAPI
Straight from the live model specification on SpicyAPI. Some creators offer more in their own apps; this is what you can call through our API today.
| Feature | Text to speech |
|---|---|
| Output formats | mp3 · wav · pcm · mulaw · alaw |
| Seed control | No |
| Negative prompt | No |
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