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Cartesia builds Sonic, a real-time text-to-speech API designed for voice agents and interactive apps. It turns text into natural-sounding speech with emotion, laughter, and human-like pacing in over 40 languages — all with very low latency. The platform supports instant voice cloning from short audio samples, enterprise-grade security (SOC 2, HIPAA, PCI), and developer-friendly APIs and SDKs. Free tier includes 20K credits. Paid plans start at $4/month.
Cartesia is AI-native. Its Sonic model generates expressive, human-like speech in real time with emotional speech synthesis, instant voice cloning, intelligent acronym handling, multilingual generation, and streaming text-to-speech for conversational AI agents.
Cartesia Sonic is a top-tier text-to-speech API for businesses building voice agents or phone bots. Speed and voice quality are best-in-class. However, this is a developer tool — you need engineering resources. Small businesses wanting a ready-made voice solution should look at platforms that use Cartesia under the hood.