Cartesia Sonic

What is Cartesia Sonic?

Cartesia's Sonic model is the lowest-latency realistic voice AI available. Built specifically for real-time conversational agents, phone systems, and live translation where every millisecond matters.

Key features

• 90 ms first-byte latency
• Voice cloning from 5 seconds of audio
• 15 languages
• Streaming API for real-time agents
• On-prem deployment option

Best for

Related comparisons

• Cartesia Sonic vs ElevenLabsElevenLabs is the gold standard for AI voice; Cartesia (with its Sonic model) is the new entrant that bet everything on real-time latency.
• Cartesia Sonic vs Eleven v4 and v4 TurboEleven v4 Turbo and Cartesia are the two text-to-speech options voice-agent builders now weigh for live conversation. Eleven v4 arrived on September 28, 2026 with a quality model for produced audio and a Turbo model at about 100 ms median latency. Cartesia built its reputation on ultra-low latency and streaming from the start, with a smaller catalogue of voices.