Ultravox by Ultravox (acquired by Inworld)
Speech-native voice AI model and API for real-time voice agents.
Voice (speech-to-text, text-to-speech)
＋ Build a stack with Ultravox Website Official pricing GitHub
Price
from $0.05 per minute after
after the free tier; plans from $100/mo
Free tier
Yes
First 30 minutes of calls free
SDK downloads
144
PyPI ultravox-client
Status
—
no public status page
How Ultravox compares
Ultravox is one of 12 APIs in the Voice (speech-to-text, text-to-speech) category on AgentGid. Its cheapest paid plan ($100 a month) is the 6th cheapest of the 6 here with a monthly plan. It is one of 11 that can be started for free. 6 of them ship an official MCP server; Ultravox does not. Its official SDK is the 10th most downloaded in the category (144 a week). See the full table.
Pricing
| Free tier | First 30 minutes of calls free |
|---|---|
| Cheapest paid plan | $100 a month |
| Usage price | $0.05 per minute after the free minutes |
| Good to know | Pay as you go allows up to 5 concurrent calls; Pro ($100/month) removes the hard concurrency caps. |
From the official pricing page, checked Oct 22, 2026. Prices change: confirm before you buy.
Use it from an agent
| MCP server | No MCP server found |
|---|---|
| PyPI | pip install ultravox-client |
| GitHub | fixie-ai/ultravox-client-sdk-python · 17 stars · last push Dec 10, 2025 |
Alternatives to Ultravox
| API | Free | Price | SDK downloads / wk | GitHub stars | MCP |
|---|---|---|---|---|---|
| OpenAI Realtime API Speech-to-speech models for real-time voice agents, priced per 1M audio and text tokens. |
— | gpt-realtime-2.1: audio $32 in / $64 out per 1M tokens;... | 107M | 11.2K | |
| ElevenLabs Text-to-speech, speech-to-text (Scribe), voice cloning and conversational voice-agent APIs. |
Free plan: 10,000 TTS characters/month (v4) | Free plan · paid from $6/mo | 2.8M | 3,150 | MCP |
| LiveKit Deploy and host AI voice and video agents with real-time communication. |
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| Deepgram Real-time and batch speech-to-text, text-to-speech and voice-agent APIs. |
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| Daily Video SDK and WebRTC infrastructure for building calls and voice AI agents. |
10,000 free minutes/month | Free plan | 510K | — | |
| Retell AI Platform and API for phone voice agents and chat agents, billed per minute or message. |
$10 in free credits | Free plan then $0.07-$0.31/min for AI voice agents; $0.002+/msg for chat agents |
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