Which should you pick?
Cartesia Sonic 3.6 costs 4 credits (headline rate) and Gemini 3.1 Flash TTS costs 12 credits (headline rate). One of the two does not publish what a full job costs, only a headline rate, so these two figures are not a like-for-like price comparison.
Cartesia Sonic 3.6 holds the stronger leaderboard position (#1 in text to audio against #8 in text to audio). Those are two different leaderboards unless the category matches — Versely ranks each capability separately.
What a job costs
Cartesia Sonic 3.6
4 credits (headline rate)
It bills per 1,000 characters of input text.
- per 1,000 characters4 credits
Gemini 3.1 Flash TTS
12 credits (headline rate)
It bills per 1,000 characters of input text.
- per 1,000 characters12 credits
All figures are Versely credits. Your plan's credit allowance is on the pricing page.
Spec comparison
| Spec | Cartesia Sonic 3.6 | Gemini 3.1 Flash TTS |
|---|---|---|
| Provider | Cartesia | |
| Cost per job | 4 credits (headline rate) | 12 credits (headline rate) |
| Billing | per 1,000 characters of input text | per 1,000 characters of input text |
| Max resolution | — | — |
| Aspect ratios | — | — |
| Durations | — | — |
| Frame rates | — | — |
| Qualities | — | — |
| Requires starting image | No | No |
| Accepts video input | No | No |
| Reference images | — | — |
| Leaderboard | #1 in text to audio | #8 in text to audio |
| Released | Aug 26, 2026 | Apr 14, 2026 |
What each one does that the other doesn't
Only Cartesia Sonic 3.6
voice clone, voice clone, emotion control, speed control, high quality, top ranked
Only Gemini 3.1 Flash TTS
expressive, audio tags, multi speaker, 30 voices
Both list: text to audio, text to speech, multilingual.
Leaderboard positions
Versely ranks each capability on its own leaderboard, so a position is only comparable between two models within the same row.
Cartesia Sonic 3.6
- Text to audio#1
Gemini 3.1 Flash TTS
- Text to audio#8
Full Cartesia Sonic 3.6 spec sheet →
Cartesia's newest and top-ranked TTS model (Sonic 3.6). 44 languages including Hindi-English code-switching, context-driven emotion without tags, speed tuning, and voice cloning. Existing cloned voices work unchanged.
Full Gemini 3.1 Flash TTS spec sheet →
Google Gemini 3.1 Flash TTS — expressive text-to-speech with 30 voices, natural-language style control, inline audio tags ([sigh], [laughing], [whispering]), multilingual synthesis, and multi-speaker dialogue.
More comparisons
Frequently asked questions
Which is cheaper, Cartesia Sonic 3.6 or Gemini 3.1 Flash TTS?+
They are not directly comparable on price: Cartesia Sonic 3.6 costs 4 credits (headline rate) and Gemini 3.1 Flash TTS costs 12 credits (headline rate), and one of those is a headline rate rather than the cost of a complete job.
What can Cartesia Sonic 3.6 do that Gemini 3.1 Flash TTS can't, or vice versa?+
Only Cartesia Sonic 3.6 lists voice clone, voice clone, emotion control, speed control, high quality, top ranked. Only Gemini 3.1 Flash TTS lists expressive, audio tags, multi speaker, 30 voices. Both list text to audio, text to speech, multilingual.
How do Cartesia Sonic 3.6 and Gemini 3.1 Flash TTS bill?+
Cartesia Sonic 3.6 bills per 1,000 characters of input text. Gemini 3.1 Flash TTS bills per 1,000 characters of input text. Both are charged in Versely credits.
Which ranks higher, Cartesia Sonic 3.6 or Gemini 3.1 Flash TTS?+
Cartesia Sonic 3.6 sits at #1 in text to audio and Gemini 3.1 Flash TTS at #8 in text to audio on Versely's live model rankings. Versely ranks each capability on its own leaderboard, so those positions are only a direct comparison when the category is the same.
Try both inside Versely
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