Data read October 27, 2026
Gradium TTS vs Fish Audio S2.1 Pro Free: TTS API comparison
On P95 latency, Gradium TTS is faster: 104.3 ms for Gradium TTS against 1,137.9 ms for Fish Audio S2.1 Pro Free.
Listener Elo is not available for both models, so voice preference is not compared. A list price is missing for at least one of the two, so price is not compared.
Gradium TTS is ranked 1 of 23; Fish Audio S2.1 Pro Free is ranked 23 of 23. Every comparison on this site uses Gradium TTS as its fixed reference, and no page says either model is better overall.
| Measure | Gradium TTS | Fish Audio S2.1 Pro Free | Ahead |
|---|---|---|---|
| Rank in the multilingual speed ranking | 1 | 23 | n/a |
| Speed tier | Headroom | Visible delay | n/a |
| Median time to first audio (ms), lower is faster | 53.7 | 793.8 | Gradium TTS |
| P95 time to first audio (ms), lower is faster | 104.3 | 1,137.9 | Gradium TTS |
| Listener Elo (Artificial Analysis) | 1,174 | n/a | n/a |
| Customer-service Elo (Artificial Analysis) | 1,241 | n/a | n/a |
| Naturalness (Speko) | 1,592 | n/a | n/a |
| Naturalness estimate (Cekura, 1 to 5) | 4.51 | n/a | n/a |
| Reading accuracy (Cekura) | 79.5% | n/a | n/a |
| Hard passages judged correct (Artificial Analysis) | n/a | n/a | n/a |
| Lowest list price per 1M characters (lower is cheaper) | $36 to $57.80 | n/a | n/a |
| Languages tested (Artificial Analysis, Speko) | 4 | 0 | Gradium TTS |
| Access | Proprietary | Proprietary | n/a |
| Streaming status | Measured | Measured | n/a |
Ahead is computed from the figures only. A latency gap under 10 ms is a tie; listener Elo values whose 95% intervals overlap are a tie. A measure one benchmark does not hold is n/a for that model and is never estimated. See the methodology and each model page for sources.
Frequently asked questions
- Is Gradium TTS faster than Fish Audio S2.1 Pro Free?
- On P95 latency, Gradium TTS is faster: 104.3 ms for Gradium TTS against 1,137.9 ms for Fish Audio S2.1 Pro Free.
- How do Gradium TTS and Fish Audio S2.1 Pro Free compare on voice quality?
- Listener Elo is not available for both models, so voice preference is not compared.
- Which is cheaper, Gradium TTS or Fish Audio S2.1 Pro Free?
- A list price is missing for at least one of the two, so price is not compared.