Smallest.ai models on the Humanness Index™
| Rank | Model | Humanness | Latency | Languages | Price / 1M chars |
|---|
| #14 | Lightning v3.1 | 62 | 420 ms | 12 | $15 |
About Smallest.ai
Smallest.ai is a research-first voice AI company whose Waves platform spans the Lightning text to speech line, the Pulse speech to text models, and the Atoms voice agent stack. Its March 2026 Lightning V3 launch claimed blind listener wins over OpenAI, Cartesia, and ElevenLabs on the EmergentTTS benchmark, positioning the family squarely at conversational agents.
Sources: smallest.ai, docs.smallest.ai
Platform and pricing
One Lightning model sits on the Index, served through the unified Waves API with HTTP, SSE, and WebSocket access and instant voice cloning from a 5 to 15 second sample via API or console. Pay-as-you-go usage bills about $0.0145 per 1,000 characters, a $14.50 per 1M effective rate, with custom enterprise and on premises options above it.
Sources: smallest.ai, docs.smallest.ai
Smallest.ai stats
- docs.smallest.ai/waves/model-cards/text-to-speech/lightning-v-3-1 (checked 2026-06-12) Lightning v3.1 model card: 12 languages with auto-detection and code-switching; the Lightning V3 launch post lists 15 including major European languages.
- smallest.ai/pricing (checked 2026-06-12) Lightning V3.1 pay-as-you-go at ~$0.0145 per 1k characters = $14.50 per 1M; the Lightning V3.1 Pro tier bills ~$0.0195 per 1k ($19.50 per 1M).
How human does your model really sound?
The benchmark is open source. Suggest a model, read the methodology, or ask us to put your voice in the arena.