Inworld

Inworld is a research lab and inference provider for realtime AI in consumer applications. It offers first party text to speech and speech to text models, access to large language models through a router, and the inference infrastructure beneath them, all through modular APIs. Inworld has also announced the acquisition of Ultravox, to extend its speech to speech research and voice agent capabilities. Its Realtime TTS 2 model targets response times under 100ms to first byte, with a Flash variant at 25ms. Features include bracketed voice direction for tone, speed and pauses, voice cloning from 15 seconds of audio, text based voice design, and support for more than 200 languages. A Realtime API supports voice agents, and the router offers more than 100 LLM models at cost. The audience is developers building companions, games, education, health and wellness products, and agent workforces at consumer scale. Pricing is published. The On Demand tier is free to start and charges $25 per million characters for TTS 2, $15 per million for TTS 2 Flash and $0.15 per hour for STT 1, with LLMs at cost. Monthly plans include credits and lower rates: Creator is $25, Builder is $100, Developer is $300 and Growth is $1,500, with speech rates falling as the tier rises. Enterprise pricing is custom. Yearly billing gives two months free, and add ons such as professional voice cloning, HIPAA and BAA are listed.