AI Voice Agent Platform

Cartesia

Real-time TTS/STT infrastructure and Line voice agent platform — built on State Space Models for sub-100ms latency

cartesia.ai Verified April 2026 San Francisco, US Founded 2023 series b

Fastest TTS/STT infrastructure in the category — Sonic-3 at 90ms, Ink at 66ms TTCT. Line adds a full agent layer on top. Infrastructure-first but increasingly a finished platform.

Pricing

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Credit-based: Free 20K/mo; Pro $4/mo 100K; Startup $39/mo 1.25M; Scale $239/mo 8M; Enterprise custom. TTS 15 credits/sec; STT 1 credit/sec ($0.13/hr on Scale); Line agents $0.06/min. LLM usage free (limited). Billed annually.

Free tier Usage-based Flat monthly Custom enterprise
View pricing page → Verified April 2026

Capabilities

Capability Cartesia
Transcription ✓
Summarization ✗
Sentiment Analysis ✗
Real-Time Agent Assist ✗
Autonomous Voice Agent ✓
Virtual Agent (Chat) ✗
Conversation Intelligence ✗
Automated QA ✗
Intelligent Routing ✗
Predictive Dialer ✗
Voice Cloning ✓
Multilingual ✓
Coaching Workflows ✗
Workforce Management ✗

Median voice latency: 90ms source

Compliance & Security

Integrations

Helpdesk

servicenow

AI Models

openaianthropicmeta llama

Other

VapiLiveKitPipecat
API documented

Alternatives to Cartesia

Frequently asked questions about Cartesia

What is Cartesia?
Fastest TTS/STT infrastructure in the category — Sonic-3 at 90ms, Ink at 66ms TTCT. Line adds a full agent layer on top. Infrastructure-first but increasingly a finished platform.
How much does Cartesia cost?
Cartesia does not publish standard per-seat pricing — plans require a custom quote. Credit-based: Free 20K/mo; Pro $4/mo 100K; Startup $39/mo 1.25M; Scale $239/mo 8M; Enterprise custom. TTS 15 credits/sec; STT 1 credit/sec ($0.13/hr on Scale); Line agents $0.06/min. LLM usage free (limited). Billed annually.
What security and compliance certifications does Cartesia have?
Cartesia is compliant with SOC 2 Type II, HIPAA, PCI DSS, and GDPR. A Business Associate Agreement (BAA) is available for healthcare deployments.
What channels does Cartesia support?
Cartesia supports voice and web chat.
What are the top alternatives to Cartesia?
Alternatives to Cartesia include Elevenlabs, Retell, Vapi, Bland, and Synthflow. See the alternatives section above for full profiles of each.