CartesiaGoogleAudio matchupSpeech output
Sonic 3.6vs.Gemini 3.8 Flash TTS
Which model is better?
Sonic 3.6 and Gemini 3.8 Flash TTS each lead in different tests.
Pick Sonic 3.6 for
Pick Gemini 3.8 Flash TTS for
Shared tests
Independent evaluators and leaderboards only, the newest shared snapshot per evaluator. With 95 % ranges a lead counts when they do not overlap; for hit rates, when it holds in a 95 % test. Without any uncertainty figure at most “slightly ahead”.
VoiceArena
Gemini 3.8 Flash TTS aheadGemini 3.8 Flash TTS is clearly ahead in 1 of 4 subtests, Sonic 3.6 in none. 3 are level.
VoiceArena TTS Elo: Mexican Spanish
95 % ranges 1,065 to 1,097 and 1,120 to 1,156, as of October 28, 2026
VoiceArena TTS Elo: Brazilian Portuguese
95 % ranges 1,062 to 1,094 and 1,084 to 1,110, as of October 28, 2026
VoiceArena TTS Elo: Hindi
95 % ranges 1,081 to 1,107 and 1,079 to 1,109, as of October 28, 2026
Show all 4 subtests
| Subtest | Sonic 3.6 | Gemini 3.8 Flash TTS | Verdict |
|---|---|---|---|
| VoiceArena TTS Elo: Mexican Spanish | 1,081 | 1,138 | Gemini 3.8 Flash TTS ahead |
| VoiceArena TTS Elo: Brazilian Portuguese | 1,078 | 1,097 | level |
| VoiceArena TTS Elo: Hindi | 1,094 | 1,094 | level |
| VoiceArena TTS Elo: US English | 1,059 | 1,059 | level |
Source · latest October 28, 2026
Artificial Analysis
Sonic 3.6 aheadSonic 3.6 is clearly ahead in 1 of 2 subtests, Gemini 3.8 Flash TTS in none. 1 is level.
Artificial Analysis Controlled Voice Arena Elo
95 % ranges 1,135 to 1,159 and 1,039 to 1,063, as of November 3, 2026
Artificial Analysis Provider Voice Arena preference
95 % ranges 1,280 to 1,306 and 1,269 to 1,295, as of November 3, 2026
Source · latest November 3, 2026
DesignArena
Sonic 3.6 slightly aheadDesignArena Audio Realism Elo
as of October 28, 2026
Source · latest October 28, 2026
All data side by side
Prices are verbatim from the provider, because audio models bill per minute, character or token.
| Sonic 3.6 | Gemini 3.8 Flash TTS | |
|---|---|---|
| Task | Speech output | Speech output |
| Developer | Cartesia | |
| Status | Active | Active |
| Released | n/a | September 22, 2026 |
| Weights | proprietary | n/a |
| Runs locally | no | no |
| Price | n/a | $0.50 per 1M text tokens through December 31, 2026, then $1 per 1M text tokens from January 1, 2027 |
| Popularity (out of 100) | 39 | 0 |