Ultravox

Ultravox is a research lab and product company that provides a real-time voice AI platform. The platform is built around a speech-native model that processes audio directly, avoiding the latency and loss of paralinguistic cues (tone, cadence, pitch) that occur in traditional speech-to-text pipelines. Ultravox manages its own inference stack and infrastructure to deliver fast, natural, and scalable voice agents. It offers developer-friendly REST APIs, SDKs for web and mobile, built-in tools, and telephony integrations. Pricing is usage-based at 5¢ per minute (including TTS) with a free Pay Go tier, a Pro tier at $100/month, and custom Enterprise plans. Ultravox also publishes open weight models on Hugging Face and is committed to open science.

Key Benefits

• Developer-friendly REST APIs for easy integration
• Speech-native model preserves paralinguistic cues
• Low latency with dedicated inference stack
• Built-in telephony integrations