Grok Voice API vs OpenAI Realtime API
How the two platforms compare on pricing, live demos, calls, integrations, and setup — highlighted where they differ.
Developer API
Grok Voice API
Realtime speech-to-speech API on Grok Voice 3.0 for building voice agents, at $0.08 per minute, with SIP calls, tool use and OpenAI Realtime compatibility.
Developer API
OpenAI Realtime API
Realtime speech-to-speech API for building low-latency voice agents over WebRTC, WebSocket, or SIP.
Highlighted rows differ between these picks
| Attribute | Grok Voice API | OpenAI Realtime API |
|---|---|---|
| Platform type | Developer API | Developer API |
| Pricing | $0.08/min $0.08/min speech-to-speech; TTS $15/M characters; STT from $0.10/hour | Usage Based pricing $32/M audio input tokens and $64/M audio output tokens for gpt-realtime |
| Test it | Open live demo | Open live demo |
| Calls | Inbound | Inbound, Outbound |
| Human handoff | Yes | Yes |
| Setup difficulty | Technical | Technical |
| Use cases | Customer Support Lead Qualification Custom Voice Apps Telephony Agents | Customer Support Appointment Scheduling Lead Qualification Custom Voice Apps |
| Useful for |
|
|
| Integrations | ||
| WebSocket | ||
| SIP | ||
| LiveKit | — | |
| Twilio | — | |
| MCP | — | |
| Web and X search | — | |
| OpenAI Realtime clients | — | |
| WebRTC | — | |
| OpenAI Agents SDK | — | |
| Custom tools | — | |
| +1 more across these tools — see each profile for the full list. | ||
Platform type
- Grok Voice API
- Developer API
- OpenAI Realtime API
- Developer API
Pricing
- Grok Voice API
$0.08/min
$0.08/min speech-to-speech; TTS $15/M characters; STT from $0.10/hour
- OpenAI Realtime API
Usage Based pricing
$32/M audio input tokens and $64/M audio output tokens for gpt-realtime
Test it
- Grok Voice API
- Open live demo
- OpenAI Realtime API
- Open live demo
Calls
- Grok Voice API
- Inbound
- OpenAI Realtime API
- Inbound, Outbound
Human handoff
- Grok Voice API
- Yes
- OpenAI Realtime API
- Yes
Setup difficulty
- Grok Voice API
- Technical
- OpenAI Realtime API
- Technical
Use cases
- Grok Voice API
- Customer SupportLead QualificationCustom Voice AppsTelephony Agents
- OpenAI Realtime API
- Customer SupportAppointment SchedulingLead QualificationCustom Voice Apps
Useful for
- Grok Voice API
- • Developer teams building realtime voice agents
- • Teams moving off the OpenAI Realtime API
- • Agents that need live web or X search
- • One flat per-minute speech-to-speech price
- OpenAI Realtime API
- • Developer teams
- • Speech-to-speech agents
- • Tool-using voice workflows
- • Custom web and phone experiences
Integrations
| Grok Voice API | OpenAI Realtime API | |
|---|---|---|
| WebSocket | ||
| SIP | ||
| LiveKit | — | |
| Twilio | — | |
| MCP | — | |
| Web and X search | — | |
| OpenAI Realtime clients | — | |
| WebRTC | — | |
| OpenAI Agents SDK | — | |
| Custom tools | — |
+1 more across these tools — see each profile for the full list.
What would these cost to run?
Enter your call volume once and see Grok Voice API and OpenAI Realtime API priced at the same usage, ranked alongside every other platform.