Smallest AI

Lightning v3.1 Pro is a text-to-speech model from Smallest AI aimed at teams building voice agents, IVR systems, and other real-time conversational products. The release focuses on the fine details that separate synthetic narration from a natural exchange, tuning where a pause lands and how a word is stressed so callers respond to the conversation rather than the model behind it. It is built for how voice systems actually run in production, generating speech in chunks , which matters for anyone deploying agents into live phone or support workflows. The Pro tier extends Lightning's coverage to 31 languages at 44.1 kHz with roughly 200ms time to first byte and streaming , and audio can be downsampled to 8 to 24 kHz for telephony . The stack also supports automatic language identification and code-switching mid-utterance across the trained voice set , which is useful for multilingual markets where a single call can shift between languages. Smallest AI was founded in 2023 by Sudarshan Kamath and Akshat Mandloi , with Kamath leading as CEO. The launch matters now because voice AI vendors are competing less on raw synthesis quality and more on conversational feel, and Lightning v3.1 Pro is the company's answer to that shift, positioned against providers like ElevenLabs, Cartesia, and OpenAI in the same category.