Cartesia vs Speechmatics

TL;DR: Cartesia offers a complete voice AI stack including both speech-to-text and text-to-speech plus voice agents, leveraging novel SSM architectures (Mamba/H-Net) for ultra-low latency across the full conversational pipeline. Speechmatics focuses exclusively on speech-to-text with deep specialization in 55+ languages and industry-specific models for medical, legal, and contact center use cases. Choose Cartesia for end-to-end voice applications where you need both listening and speaking capabilities, or Speechmatics for best-in-class multilingual transcription with vertical-specific accuracy.