Lightning v3.1 measured on 2 of 3 Text to speech benchmarks2
BenchmarkByScoreRank
No benchmark matches
$25per 1M characters
1,021arena Elo
Mar 2026released
Exact native tariff; see source for billing scope.Price covers
Ranking?
Full ranking →···
78Chatterbox1,025.179Lightning v3.11,020.580Raon SpeechLM1,004.6Strong at
Alternatives?
ModelScoreCostPriceWhat changes
CheaperQwen Audio 3.1 TTS Pluswins 84%-23%$19.31KBetterKokoro 82M v1.0Openwins 56%-96%$0.99
OpenFish Audio Drama 3 Previewwins 78%-40%$15CheaperQwen Audio 3.0 TTS Pluswins 81%-23%$19.31SCheaperSimba 3.2wins 79%-74%$6.58ModelScoreCostPriceWhat changes
Qwen Audio 3.1 TTS Pluswins 84%-23%$19.31Qwen Audio 3.0 TTS Pluswins 81%-23%$19.31SSimba 3.2wins 79%-74%$6.58Fish Audio Drama 3 PreviewOpenwins 78%-40%$15
Voxtral 3 TTSwins 76%-48%$13ModelScoreCostPriceWhat changes
KKokoro 82M v1.0Openwins 56%-96%$0.99SSimba 3.2wins 79%-74%$6.58SSimba 3.0wins 64%-74%$6.58
Gemini 2.5 Flash Lite TTSwins 59%-63%$9.15Gemini 2.5 Flash TTS (Dec 2025)wins 57%-63%$9.15ModelScoreCostPriceWhat changes
Fish Audio Drama 3 PreviewOpenwins 78%-40%$15BBreeze TTS 2Openwins 77%+36%$34AMing 3.0 TTSOpenwins 73%——Fish Audio S2 ProOpenwins 63%-40%$15
Step Audio EditX (Mar 2026)Openwins 61%——ModelScoreCostPriceWhat changes
SLightning V3.1 Pro (Jul 2026)wins 71%-22%$19.50All Smallest.ai models →FAQ
How much does Lightning v3.1 cost?›
$25 per 1M characters.
Is Lightning v3.1 free to use?›
There is no free API; it costs $25 per 1M characters.
How good is Lightning v3.1, and what is it best at?›
#78 of 96 in Text to speech.
Is Lightning v3.1 better than Chatterbox?›
On AA TTS provider voice, Lightning v3.1 scores 1,020.5 vs 1,025.1 — about the same. It is 0% more expensive.
When was Lightning v3.1 released? Is there a newer version?›
Released 2026-03-24. It is the current version in its line.
Is Lightning v3.1 open source?›
No, Lightning v3.1 is a closed model available through an API. The closest open-weights option here is Fish Audio Drama 3 Preview.
What is Lightning v3.1?›
Lightning v3.1 is a closed speech & voice model from Smallest.ai, released Mar 2026.
What are the best alternatives to Lightning v3.1?›
Qwen Audio 3.1 TTS Plus (cheaper), Kokoro 82M v1.0 (better), Fish Audio Drama 3 Preview (open weights).