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Cartesia
Cartesia offers Sonic-3, a state-of-the-art text-to-speech (TTS) API designed for creating highly natural and expressive AI voice agents.
Our verdict
Who it's for
Real-time text-to-speech API with AI laughter, emotion, and ultra-low latency for voice agents.
Who should look elsewhere
Advanced features like pro voice cloning require higher-tier plans
Pros
- +Highly natural and expressive AI voices with emotion and laughter
- +Exceptional low latency for real-time conversations
- +Intelligent handling of complex linguistic elements like acronyms
- +Comprehensive suite for both TTS and voice agent development
- +Strong enterprise focus with security, compliance, and scalability features
Cons
- −Advanced features like pro voice cloning require higher-tier plans
- −Pricing model based on credits might be complex for some users to estimate
- −Focus on technical teams for agent development might have a learning curve
Key features
- ✓Sonic-3 Text-to-Speech API
- ✓AI-generated laughter and emotions
- ✓Ultra-low latency (90ms time-to-first-audio)
- ✓Context-savvy accuracy for acronyms and initialisms
- ✓Supports 42 languages
- ✓Ink-Whisper streaming speech-to-text model
- ✓Line voice agent development platform (code-first)
- ✓Voice cloning (instant and pro)
Pricing
| Plan | Price | Billing | Notes |
|---|---|---|---|
| Free | $0 | month | 20K credits for models; $1 prepaid for agents; Personal use |
| Pro | $4 | month | 100K credits for models; $5 prepaid for agents; Instant voice cloning |
| Startup | $39 | month | 1.25M credits for models; $49 prepaid for agents; Pro voice cloning |
| Scale | $239 | month | 8M credits for models; $299 prepaid for agents; Priority support |
| Enterprise | — | month | Custom usage pricing; Custom concurrency; Enterprise support via slack |