TTS API comparison 2026
ElevenLabs Eleven v3 Conversational vs Google Gemini 3.8 Flash TTS ElevenLabs vs Google · text-to-speech for voice agents
ElevenLabs Eleven v3 Conversational ranks 10th of 112 with 56.8/100; Google Gemini 3.8 Flash TTS ranks 24th with 29.7/100: a gap of 27.1 points on the same public rules, built on Coval, Speko and Artificial Analysis.
Data checked on September 30, 2026 · Coval 30-day window ending October 1, 2026 · updated after each benchmark capture
Side-by-side benchmark
| Measure | ElevenLabs Eleven v3 Conversational | Google Gemini 3.8 Flash TTS |
|---|---|---|
| Overall score | 56.8/100 | 29.7/100 |
| Rank | 10th of 112 | 24th of 112 |
| Real-time speed /60 | 29.9 | 0 |
| Voice quality /20 | 17.2 | 19.3 |
| Accuracy /15 | 8.2 | 6.9 |
| Price /5 | 1.5 | 3.5 |
| P50 / median time-to-first-audio Coval, 30-day window | 323.1 ms | not measured |
| P99 time-to-first-audio (slowest turns) Coval, 30-day window | 497.7 ms | not measured |
| Latency consistency (standard deviation) Coval, 30-day window | 52.9 ms | not measured |
| P50 time-to-first-audio, US East Speko | 266 ms | 1031 ms |
| Accuracy: word error rate (WER) Coval, 30-day window | 4.3% | not measured |
| Pronunciation robustness (0 to 1) Speko | 0.3 | 0.7 |
| Speech Arena Elo (blind listener preference) Artificial Analysis | 1200 | 1272 |
| Naturalness (Elo) Speko | 1590 | 1642 |
| Price per 1M characters Artificial Analysis | 50 USD | 16.5 USD |
Choose ElevenLabs Eleven v3 Conversational if…
- → Ranks 10th of 112 in the overall benchmark, against 24th for Google Gemini 3.8 Flash TTS
- → Better P50 time-to-first-audio, US East: 266 ms vs 1031 ms (Speko)
Choose Google Gemini 3.8 Flash TTS if…
- → Better pronunciation robustness (0 to 1): 0.7 vs 0.3 (Speko)
- → Better speech Arena Elo (blind listener preference): 1272 vs 1200 (Artificial Analysis)
- → Better naturalness (Elo): 1642 vs 1590 (Speko)
- → Better price per 1M characters: 16.5 USD vs 50 USD (Artificial Analysis)
Frequently asked questions
- What is the difference between ElevenLabs Eleven v3 Conversational and Google Gemini 3.8 Flash TTS?
- In the 2026 TTS API benchmark, ElevenLabs Eleven v3 Conversational ranks 10th of 112 with 56.8/100 and Google Gemini 3.8 Flash TTS ranks 24th with 29.7/100, a gap of 27.1 points on the same rules.
- Which is faster for real-time voice agents, ElevenLabs Eleven v3 Conversational or Google Gemini 3.8 Flash TTS?
- On Coval's 30-day window ending October 1, 2026, the P50 time-to-first-audio is 323.1 ms for ElevenLabs Eleven v3 Conversational and not measured for Google Gemini 3.8 Flash TTS; the P99 is 497.7 ms and not measured.
- On which criteria does Google Gemini 3.8 Flash TTS beat ElevenLabs Eleven v3 Conversational?
- Google Gemini 3.8 Flash TTS scores higher on Voice quality (19.3 vs 17.2 out of 20), Price (3.5 vs 1.5 out of 5).
- How are these two text-to-speech APIs scored?
- Both are scored by the same public rules: 4 criteria, 100 points (Real-time speed 60, Voice quality 20, Accuracy 15, Price 5), computed from three independent benchmarks: Coval, Speko and Artificial Analysis. A measurement a benchmark does not publish counts zero, and the model page says why.
- Can these numbers be checked?
- Yes. Each model page lists every measurement with its source and date, and links to the benchmark page it comes from. The rules are on the methodology page.