Cartesia · read on October 27, 2026
Cartesia Sonic 3.6
Cartesia Sonic 3.6 is a TTS (text-to-speech) model from Cartesia. Coval measures its P95 time to first audio at 374.4 ms, which puts it in the Visible delay speed tier. It ranks 18 of 86 in the full ranking.
- Speed tier
- Visible delay
- P95 / median
- 374.4 ms / 285.8 ms
- Listener Elo
- 1,292
- Price per 1M chars
- $39.2 to $50
Where it ranks
Full ranking: 18 of 86. Use case ranks, by speed:
The tier and the ranks are computed by this site from the benchmarks' figures, not declared by Cartesia.
Measurements and sources
Coval
| Median time to first audio (P50) | 285.8 ms |
| Time to first audio, P95 | 374.4 ms |
| Time to first audio, mean | 292.1 ms |
| Time to first audio, P90 | 350.6 ms |
| Timed requests | 2,807 |
Speko
| Naturalness score | 1,578 |
| Latency, board chart | 130 ms |
| Latency, model page sweep (median) | 120 ms |
| Numbers and dates pronunciation | 0.21 |
Artificial Analysis
| Listener Elo | 1,292 |
| Listener Elo, 95% interval | 14 |
| Listener Elo, customer service | 1,331 |
| Hard passages pronounced correctly | 74.5% |
Cekura
| Time to first audio, streamed text | 270 ms |
| Time to first audio, text sent whole | 286 ms |
| Reading accuracy | 74.9% |
| Estimated naturalness (1 to 5) | 4.41 |
Details
| Provider | Cartesia |
| Access | Proprietary |
| Streaming | A benchmark measures its time to first audio |
| Features listed by Coval | emotion-control, multilingual, voice-cloning |
| Languages tested | Spanish, German, French, Portuguese, Japanese, Chinese, Arabic, Hindi, Vietnamese |
| Measured by | Artificial Analysis, Cekura, Coval, Speko |
| Official site | www.cartesia.ai |
Sources
- https://artificialanalysis.ai/text-to-speech (read on October 27, 2026)
- https://artificialanalysis.ai/text-to-speech/leaderboard/provider-voice (read on October 27, 2026)
- https://benchmarks.cekura.ai/text-to-speech (read on October 27, 2026)
- https://benchmarks-api-6wxgp27p2a-ue.a.run.app/v1/results/aggregates?benchmark=TTS&window=30d&include_series=false (read on October 27, 2026)
- https://benchmarks.speko.ai/tts/ (read on October 27, 2026)
Values are copied from these pages on the date shown. Vendor and model name agree in every source that lists it.
Compare it with the reference model: Gradium TTS vs Cartesia Sonic 3.6.