Cartesia

Realtime voice AI platform with the Sonic family of low-latency TTS models

0Design & CreativeFreemium

Editorial Review

Cartesia emerged in 2023-2024 as the realtime-voice answer to ElevenLabs' studio-quality dominance. Where ElevenLabs prioritized maximum naturalism and creator workflows, Cartesia prioritized latency — Sonic models stream first audio in under 100ms, which is the threshold below which voice agents feel responsive rather than awkward. For voice-agent and IVR builders, Cartesia is frequently the best technical choice precisely because of that latency profile; voice clones are good (not always quite as nuanced as ElevenLabs' top tier) but the realtime experience is materially better. The free tier supports prototyping; paid tiers scale with usage. As voice agents become more central to AI products in 2026, Cartesia's specialization positions it well — though ElevenLabs has also closed the latency gap meaningfully with their newer Turbo and Realtime models.

Key Features

Sonic-class TTS modelsSub-100ms streaming latencyVoice cloning from short samples

About Cartesia

Cartesia is a voice-AI platform centered on the Sonic family of text-to-speech models, optimized for sub-100ms latency and natural-sounding multilingual output. Used in voice agents, IVR systems, and audio content production.

Pricing

ModelFreemium

Free tier

Best For

Solo

Small (2-10)

Medium (11-50)

Mid-Market (51-200)

Enterprise (200+)

Integrations

WebSocket APIREST APILiveKitPipecat

See Cartesia compared

ElevenLabs vs Cartesia vs Vapi