Cartesia Sonic

Cartesia provides a high-performance voice AI platform designed for developers who need to build natural, real-time conversational experiences. It directly addresses the core challenges of latency and robotic speech, providing the tools you need to build exceptionally fast, responsive, and natural-sounding voice applications that truly engage your users.

Key Features

Cartesia is built on a foundation of two powerful, purpose-built model families for Text-to-Speech (TTS) and Speech-to-Text (STT).

• ⚡ Ultra-Low Latency Text-to-Speech (Sonic) Our flagship Sonic models generate incredibly realistic and expressive speech with world-leading speed. With a time-to-first-audio of under 40ms, Sonic-Turbo eliminates the awkward pauses that plague typical voice AI, enabling conversations that feel genuinely fluid and interactive. The platform also includes high-fidelity voice cloning to create consistent, brand-aligned voices at scale.

• 🎙️ Real-World Accurate Speech-to-Text (Ink-Whisper) Ink-Whisper is engineered for the complexities of real-world audio. It delivers fast, precise transcriptions even with challenging conditions like background noise, telephony compression, diverse accents, and domain-specific jargon. This accuracy ensures your AI agent correctly understands user intent the first time, leading to more effective and less frustrating interactions.

• 🔒 Enterprise-Grade Security & Flexible Deployment Your data is protected by industry-leading compliance standards, including SOC 2 Type 2, HIPAA, and PCI. Cartesia offers flexible deployment options—from a secure cloud API to managed in-VPC or fully on-premise installations—giving you complete control over your data to meet any security or residency requirements.

Use Cases

Here’s how you can leverage Cartesia to build superior voice-enabled products:

1. Responsive AI Voice Agents: Power virtual agents for customer support, sales, or logistics that can understand and respond instantly. By eliminating lag, you create a seamless conversational flow that improves customer satisfaction and operational efficiency, allowing your agent to spend more time thinking and acting, not waiting.

2. Immersive Gaming and Digital Avatars: Bring non-player characters (NPCs) and digital avatars to life with dynamic, expressive voices that can react in real-time to player actions. Use the voice cloning feature to create unique and memorable character voices, making your virtual worlds more believable and engaging.

3. Scalable Content Creation and Dubbing: Automate the narration for podcasts, audiobooks, or news articles with natural-sounding voices in over 15 languages. The platform's speed and quality make it ideal for dubbing video content, allowing you to localize your media for a global audience quickly and cost-effectively.

Why Choose Cartesia?

Cartesia is engineered from the ground up to solve the specific, practical challenges developers face when building interactive voice AI.

• Unmatched Speed for Truly Fluid Conversations: Latency is the enemy of natural conversation. Cartesia’s models are among the fastest available, with a benchmarked 40ms time-to-first-audio for TTS and 66ms time-to-complete-transcript for STT. This performance doesn't just reduce waiting; it creates the necessary time budget for the rest of your AI stack to process information and deliver an intelligent response without delay.

• Purpose-Built for Real-World Complexity: Standard transcription models often fail when faced with imperfect audio. Ink-Whisper is different. It is specifically optimized to handle the messy reality of phone calls and public environments, accurately transcribing speech despite background chatter, audio compression artifacts, and conversational disfluencies like "um" or "ah."

• Developer-First with Enterprise-Ready Infrastructure: Get started in minutes with a clear API, comprehensive documentation, and seamless integrations for platforms like Twilio, LiveKit, and Pipecat. As you scale, you can rely on an infrastructure with 99.9% uptime, priority support SLAs, and the enterprise-grade compliance necessary for regulated industries like healthcare and finance.

Conclusion

Cartesia empowers you to move beyond clunky, delayed voice interactions and build the next generation of conversational AI. By providing the fastest, most realistic, and most reliable voice models in a developer-friendly platform, Cartesia gives you the foundation to create experiences that are not just functional, but genuinely impressive.

Explore the documentation to see how Cartesia can elevate your next project!