Grok Voice Models by xAI
xAIProprietary
xAI releases · 16 in the last 12 months · this family litChangelog →
2 models2026
Last refreshed 2026-09-21. Next refresh: weekly.
Capabilities
Multimodal1 of 2 models
Reasoning1 of 2 models
JSON / Tool use1 of 2 models
Structured Outputs1 of 2 models
Links
WebsiteAbout
xAI's Grok Voice family of full-duplex voice agent models for enterprise workflows. Designed for complex, multi-step customer support, sales, and enterprise applications with real-time reasoning, structured data capture, and broad language support. The family is evaluated on the τ-voice Bench leaderboard for full-duplex voice agents under realistic conditions.
Decision facts
- Best fit
- speech recognitionaudiorealtime voice
- Capability starting point
- Grok Voice Think Fast 1.0 with reasoning, JSON / Tool use, structured outputs, and multimodal inputs
- Lowest tracked input
- Not tracked
- Closest related family
- Grok 1
Current Variants
Use-when guidance is based on each model's tracked capabilities, context window, release date, and replacement status.
2 in view
Grok Voice Transcribe 2.0Current
Use when the workload needs speech recognition and audio.
2026-09speech recognitionaudio
Grok Voice Think Fast 1.0Current
Use when the workload needs realtime voice, reasoning, and JSON / Tool use.
2026-04realtime voicereasoningJSON / Tool use
| Model | Use when | Released | Signals | Status |
|---|---|---|---|---|
| Grok Voice Transcribe 2.0 | Use when the workload needs speech recognition and audio. | 2026-09 | speech recognitionaudio | Current |
| Grok Voice Think Fast 1.0 | Use when the workload needs realtime voice, reasoning, and JSON / Tool use. | 2026-04 | realtime voicereasoningJSON / Tool use | Current |
Release Timeline
2 release groups2026-09
1 current
Grok Voice Transcribe 2.0
Currentspeech recognitionaudio
2026-04
1 current
Grok Voice Think Fast 1.0
Currentrealtime voicereasoningJSON / Tool use
Specifications(2 models)
| Model | Released | Multimodal | Reasoning | JSON / Tool use | Structured Outputs |
|---|---|---|---|---|---|
| Grok Voice Transcribe 2.0 | 2026-09 | No | No | No | No |
| Grok Voice Think Fast 1.0 | 2026-04 | Yes | Yes | Yes | Yes |
