Cartesia

Cartesia is a voice AI company that builds fast, natural sounding speech models for real time conversations. It was started by researchers who helped create State Space Models, a design built for speed and understanding long stretches of context.

The platform gives you three main tools. Sonic turns text into natural speech, Ink turns speech into accurate text, and Line lets you build and run full voice agents that use both together.

Cartesia is made mainly for developers and companies who want to add voice features to their own apps, support lines, or automated calling systems, rather than everyday casual users.

You can start for free and move up to paid plans as your usage grows, with custom options for larger teams.

• Natural sounding text to speech in 40+ languages

• Accurate speech to text with turn detection

• Code first voice agent platform

• Instant and professional voice cloning

• Batch outbound calling

• Cloud, on premise, and on device deployment

• Zero data retention and call redaction

• Free plan with paid plans that scale up