Data read October 27, 2026
Gradium TTS vs OpenAI TTS-1: TTS API comparison
Speed cannot be compared: Coval does not measure OpenAI TTS-1, so it has no P95 here.
On Artificial Analysis listener Elo, Gradium TTS is ahead (1,174 for Gradium TTS, 1,088 for OpenAI TTS-1). List price per million characters: $36 to $57.80 for Gradium TTS, $15 for OpenAI TTS-1.
Gradium TTS is ranked 1 of 23; OpenAI TTS-1 is not in the multilingual speed ranking. Every comparison on this site uses Gradium TTS as its fixed reference, and no page says either model is better overall.
| Measure | Gradium TTS | OpenAI TTS-1 | Ahead |
|---|---|---|---|
| Rank in the multilingual speed ranking | 1 | not ranked | n/a |
| Speed tier | Headroom | n/a | n/a |
| Median time to first audio (ms), lower is faster | 53.7 | n/a | n/a |
| P95 time to first audio (ms), lower is faster | 104.3 | n/a | n/a |
| Listener Elo (Artificial Analysis) | 1,174 | 1,088 | Gradium TTS |
| Customer-service Elo (Artificial Analysis) | 1,241 | 1,105 | Gradium TTS |
| 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 | $15 | OpenAI TTS-1 |
| Languages tested (Artificial Analysis, Speko) | 4 | 0 | Gradium TTS |
| Access | Proprietary | Proprietary | n/a |
| Streaming status | Measured | Vendor documentation | 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 OpenAI TTS-1?
- Speed cannot be compared: Coval does not measure OpenAI TTS-1, so it has no P95 here.
- How do Gradium TTS and OpenAI TTS-1 compare on voice quality?
- On Artificial Analysis listener Elo, Gradium TTS is ahead (1,174 for Gradium TTS, 1,088 for OpenAI TTS-1).
- Which is cheaper, Gradium TTS or OpenAI TTS-1?
- List price per million characters: $36 to $57.80 for Gradium TTS, $15 for OpenAI TTS-1.