audio model comparison
Eleven Flash v2.5 vs Sonic 3.6
Eleven Flash v2.5 and Sonic 3.6 are both current audio models, from ElevenLabs and Cartesia. Eleven Flash v2.5 is 38% cheaper per character than Sonic 3.6, $0.00004 vs $0.000065. On Artificial Analysis Speech Arena, Eleven Flash v2.5 scores 1078 Elo and Sonic 3.6 1286 Elo (Artificial Analysis, measured October 13, 2026).
Data verified October 13, 2026 · Dataset 2026-10-13
Side by side
Standard-tier prices in effect today. The better value in each row is highlighted.
| Fact | Eleven Flash v2.5 | Sonic 3.6 |
|---|---|---|
| Price per character | $0.00004 (better) | $0.000065 |
| Artificial Analysis Speech Arena | 1078 Elo (#11 of 11) | 1286 Elo (#3 of 11) (better) |
| Provider | ElevenLabs | Cartesia |
| Release date | Not reported | August 27, 2026 |
| Access | API only | API only |
| Context window | Not reported | Not reported |
| Max output | Not reported | Not reported |
| Input | text | text |
| Output | audio | audio |
When to choose each
Eleven Flash v2.5
Best for
- Low-latency multilingual speech
Watch out for
- Built for latency rather than expressiveness; Eleven v4 Turbo now sells at the same $0.04 per 1,000 characters
Sonic 3.6
Best for
- Multilingual speech for voice agents
- Indian-language and Hinglish speech
Watch out for
- Credit-based plans only (1 credit per character); the recorded rate is the Pro plan overage of $65 per 1M characters, falling to $38 on the Scale plan
- Cartesia does not state latency figures for this version
Eleven Flash v2.5 vs Sonic 3.6 FAQ
Which is cheaper, Eleven Flash v2.5 or Sonic 3.6?
Eleven Flash v2.5 is 38% cheaper per character than Sonic 3.6, $0.00004 vs $0.000065.
Which scores higher on independent benchmarks, Eleven Flash v2.5 or Sonic 3.6?
Sonic 3.6 leads on Artificial Analysis Speech Arena, 1286 Elo to 1078 Elo. Scores are independent evaluations, not either vendor's launch figures.
Related comparisons
- Eleven Flash v2.5 vs Eleven Multilingual v2
- Eleven Flash v2.5 vs Eleven v3
- Eleven Flash v2.5 vs Eleven v4
- Eleven Flash v2.5 vs Eleven v4 Turbo
- Eleven Flash v2.5 vs TTS-1
- Eleven Multilingual v2 vs Sonic 3.6
- Eleven v3 vs Sonic 3.6
- Eleven v4 Turbo vs Sonic 3.6
- Eleven v4 vs Sonic 3.6
- Gemini 3.8 Flash TTS vs Sonic 3.6
Production evaluation
Choosing between Eleven Flash v2.5 and Sonic 3.6?
Public benchmarks narrow the shortlist. We run both on your own tasks, data and cost limits, then build the routing and review controls to run the winner in production.
- A head-to-head evaluation on your real workload
- Routing between models by cost and difficulty