ElevenLabs vs Cartesia: Text-to-Speechlatency & accuracy
Measured head-to-head, not marketing: ElevenLabs currently leads both measured axes — median TTFA and Word Error Rate. Independent data, refreshed daily, on identical inputs. Voice quality and price are not measured.
ElevenLabs or Cartesia — which is better?
Each provider's best model on each measured axis, last 7d. Lower is better on both:
| Axis | ElevenLabs (best model) | Cartesia (best model) | Measured winner |
|---|---|---|---|
| Speed — median TTFA | eleven_flash_v2_5 · 210 ms | sonic-3.5 · 277 ms | ElevenLabs |
| Accuracy — avg WER | eleven_multilingual_v2 · 4.5% | sonic-3.5 · 6.0% | ElevenLabs |
Not measured here: voice quality / naturalness and price — treat those as vendor claims until measured. Full leaderboard context: the independent text-to-speech benchmark →
Every ElevenLabs and Cartesia model, measured
All benchmarked models from both providers on the same pinned dataset, ranked fastest-first (median TTFA), last 7d:
| Model | Provider | TTFA median | TTFA p95 | WER | Samples |
|---|---|---|---|---|---|
| eleven_flash_v2_5 | ElevenLabs | 210 ms | 2,871 ms | 5.7% | 3,360 |
| sonic-3.5 | Cartesia | 277 ms | 355 ms | 6.0% | 3,358 |
| sonic-3 | Cartesia | 461 ms | 826 ms | 6.7% | 3,356 |
| eleven_v3 | ElevenLabs | 582 ms | 3,222 ms | 5.4% | 1,729 |
| eleven_multilingual_v2 | ElevenLabs | 1,248 ms | 1,626 ms | 4.5% | 3,075 |
Independent data, by Coval
Numbers are from the voice benchmark by Coval, a voice-AI evaluation platform that does not sell TTS models — it measures every provider as a neutral third party on a pinned dataset under production-realistic conditions. Openbenchmarks mirrors the results daily with attribution; methodology and runner are open-source and reproducible.
ElevenLabs vs Cartesia — common questions
Is ElevenLabs faster than Cartesia for text-to-speech?
On the current 7d window, ElevenLabs's fastest model (eleven_flash_v2_5) has a median TTFA of 210 ms, vs 277 ms for Cartesia's fastest (sonic-3.5) — so ElevenLabs is faster on measured median latency. Distributions matter too: p95 is 2,871 ms for ElevenLabs vs 355 ms for Cartesia.
Which is more accurate, ElevenLabs or Cartesia?
By Word Error Rate: ElevenLabs's best model (eleven_multilingual_v2) averages 4.5%, vs 6.0% for Cartesia's best (sonic-3.5) — ElevenLabs leads on measured accuracy. Lower is better; WER is measured on identical inputs under production-realistic conditions.
Which should I pick — ElevenLabs or Cartesia?
ElevenLabs currently leads both measured axes (median TTFA and WER). Full per-model distributions are in the table below; voice quality / naturalness and price are not measured here.
Where does this data come from?
The independent voice benchmark by Coval, a voice-AI evaluation platform that does not sell TTS models. Every model runs the same pinned dataset under production-realistic conditions, re-run roughly every 30 minutes; Openbenchmarks mirrors the results daily with attribution. Methodology and runner are open-source (Apache-2.0).