Lightning v3.1 Pro text-to-speech model
Smallest.ai
Lightning v3.1 Pro is a text-to-speech (TTS) model from Smallest.ai. It has no Artificial Analysis score yet. On TTS Arena V2 it scores Elo 1525 (±27, 616 votes).
Key facts
- Provider
- Smallest.ai
- TTS Arena Elo (uncertainty)
- 1525 ±27
- TTS Arena votes
- 616
- TTS Arena win rate
- 52.1%
Not yet available: AA rank, AA Elo (95% CI), AA samples, Price (per 1M chars), Released, Open weights, License, Voices tested by AA, Languages, Voice cloning
Who it is for (from the data)
- Only TTS Arena community results so far (Elo 1525, 616 votes) and no Artificial Analysis rank; suited to people willing to test it themselves.
- Use via Smallest.ai's service or API; the sources do not list it as open weights.
- Existing Smallest.ai users: this vendor has 3 models on the board.
Nearby models
By TTS Arena Elo; this model highlighted| # | Model | AA Elo | Arena Elo | Price $/1M chars | Open weights | Δ |
|---|---|---|---|---|---|---|
| 8 | DDeepdub eTTS 3.2 Deepdub | – | 1532 | – | – | +7 |
| 9 |  Speech 2.8 HD MiniMax | 1174 | 1529 | $100 | – | +4 |
| 10 | IInworld TTS Inworld | – | 1528 | – | – | +3 |
| 11 | SLightning v3.1 Pro Smallest.ai | – | 1525 | – | – | |
| 12 | HOctave TTS Hume AI | 1040 | 1515 | $87.5 | – | -10 |
| 13 | GGradium TTS (pre-2026.08) Gradium | – | 1515 | – | – | -10 |
| 14 |  OpenAudio S2 Fish Audio | – | 1514 | – | – | -11 |
Alternatives · More from Smallest.ai
| # | Model | AA Elo | Arena Elo | Price $/1M chars | Open weights |
|---|---|---|---|---|---|
| 8 | SLightning V3.1 Pro (Oct 2026) Smallest.ai | 1266 | – | – | – |
| 80 | SLightning v3.1 Smallest.ai | 1022 | – | $25 | – |
Alternatives · Top 5 open-weight by AA Elo
| # | Model | AA Elo | Arena Elo | Price $/1M chars | Open weights |
|---|---|---|---|---|---|
| 11 | Fish Audio Drama 3 Preview Fish Audio | 1240 | – | $15 | Open |
| 12 | BBreeze TTS 2 BreezeBlue | 1228 | – | $34 | Open |
| 23 |  Ming-3.0-tts Ant Group | 1187 | – | – | Open |
| 39 | Fish Audio S2 Pro Fish Audio | 1109 | – | $15 | Open |
| 42 |  Step Audio EditX (Mar 2026) StepFun | 1099 | – | – | Open |
How to read the scores
- AA Elo: the Elo score from the Artificial Analysis speech arena. Listeners blind-compare two clips and pick the better one; "±" is the 95% confidence interval.
- TTS Arena Elo: Elo from TTS Arena V2 community blind votes. The two boards use different scales, so do not subtract one from the other.
- If the gap between two models is smaller than their combined intervals, the order is not statistically reliable; treat them as the same tier. More samples or votes mean narrower intervals.
FAQ
Where does Lightning v3.1 Pro rank among TTS models?
As of Oct 29, 2026, Lightning v3.1 Pro has no Artificial Analysis score; its TTS Arena V2 Elo is 1525 (616 votes).
Is Lightning v3.1 Pro open source?
The sources do not list Lightning v3.1 Pro as open-weight; it is generally used through the Smallest.ai API.
Which top-10 TTS model is cheapest?
Among the AA top 10, the lowest list price is Simba 3.2 (SpeechifyAI) at $6.6 per 1M characters, Elo 1249.
What is the best open-source TTS model?
By AA Elo, the top open-weight model is Fish Audio Drama 3 Preview by Fish Audio (Elo 1240, #11 overall); 18 open-weight models have an AA score.
Who makes Lightning v3.1 Pro?
Lightning v3.1 Pro is made by Smallest.ai.
How reliable is Lightning v3.1 Pro's score?
The scores are based on 616 TTS Arena votes. More samples and narrower intervals mean a more stable rank.
Sources
17NAS syncs the upstream leaderboards daily; this page's data was synced on Oct 29, 2026.
"–" means the upstream sources do not provide this value; we do not guess.