SpaceXAI just released Grok Voice 3.0. Grok Voice 3.0 is a SpaceXAI speech-to-speech model that listens, reasons, calls tools and speaks. It now ranks first on the Artificial Analysis Speech-to-Speech Index with a score of 86.9. For developers, the endpoint, events and $0.08 per minute price are unchanged from Grok Voice 2.0.
TL;DR
- Runs on: SpaceXAI’s hosted Voice Agent API only. No open weights, no local or quantized variants.
- Performance: Highest Index score of any model Artificial Analysis currently ranks.
- Best: 86.9 on the AA Speech-to-Speech Index, ranked #1.
- Worst: 71.6% on τ-Voice, behind GPT-Live-1 (Astra, medium) at 74.5%.
- Bottom line:
- Best: top composite score at 0.81 s time to first audio.
- Worst: not the leader on agentic task resolution or raw speech reasoning.
What is Grok Voice 3.0?
Grok Voice 3.0 is SpaceXAI’s flagship realtime voice model, exposed as grok-voice-3.0 on the /v1/realtime WebSocket endpoint. The grok-voice-latest alias already points to it, so existing agents switched automatically.
SpaceXAI has not published parameter counts or architecture details. Reasoning is on by default (reasoning.effort: "high") and can be set to "none" for faster turns. Server-side voice activity detection handles barge-in. Tools run inside the session: collections search, web search, X search, remote MCP servers and custom functions.
How does Grok Voice 3.0 perform on benchmarks?
The AA Speech-to-Speech Index is an equal-weighted average of 4 components. Those are Big Bench Audio reasoning, τ-Voice agentic performance, Speech Agent Arena preference and task success rate.
Grok Voice 3.0 scores 86.9. GPT-Live-1 (Astra, medium) scores 83.2, Gemini 3.8 Live Extended Thinking 82.6. Grok Voice 2.0 scored 81.3.
Component results are strong, not uniformly first:
- Big Bench Audio: 98.5%, ranked 4th. StepAudio 3 Realtime leads at 99.7%.
- Full Duplex Bench: 97.0%, ranked 4th. StepAudio 3 Realtime leads at 98.9%.
- Task success rate: 94.8%, up from 94.6% for Grok Voice 2.0.
- Speech Agent Arena Elo: 1070, the highest among the 4 models compared here.
- τ-Voice: 71.6%, up from 56.5%, but below GPT-Live-1 (Astra, medium) at 74.5%.
ServiceNow’s EVA-Bench scores enterprise voice agents on accuracy and experience. SpaceXAI reports a top accuracy score of 74%.
Is Grok Voice 3.0 fast and cheap?
Artificial Analysis measures 0.81 s time to first audio. GPT-Live-1 (Astra, medium) measures 1.34 s, so SpaceXAI’s “40% lower latency” claim checks out. Grok Voice 2.0 was faster, though, at 0.70 s.
On cost, SpaceXAI cites Artificial Analysis cost per Big Bench Audio task. Grok Voice 3.0 costs $0.025 per task, versus $0.030 for GPT-Live-1 (Astra, medium) and $0.055 for GPT-Realtime-2.1 (High). On AA’s cost per hour of input audio, Gemini 3.8 Live Extended Thinking is cheaper: $3.50 versus $4.80.
List prices are not directly comparable. GPT-Live-1 costs $0.05 per minute, but backend model and tool usage is billed separately. Gemini 3.8 Live bills audio per minute plus text tokens.
How does Grok Voice 3.0 compare to GPT-Live-1 and Gemini 3.8 Live?
| Feature | Grok Voice 3.0 | Grok Voice 2.0 | GPT-Live-1 (Astra, medium) | Gemini 3.8 Live Extended Thinking |
|---|---|---|---|---|
| Developer | SpaceXAI | SpaceXAI | OpenAI | |
| Parameters | Not disclosed | Not disclosed | Not disclosed | Not disclosed |
| Context length | Not disclosed | Not disclosed | Not disclosed | Not disclosed |
| Weights | Closed, API only | Closed, deprecated | Closed, API only | Closed, API only |
| Input / output | Audio, text / audio, text | Audio, text / audio, text | Audio, text / audio, text | Text, image, video, audio / audio, text |
| AA Speech-to-Speech Index | 86.9 | 81.3 | 83.2 | 82.6 |
| Big Bench Audio | 98.5% | 97.2% | 90.1% | 97.7% |
| τ-Voice | 71.6% | 56.5% | 74.5% | 68.6% |
| Full Duplex Bench | 97.0% | 95.1% | 94.9% | 91.9% |
| Task success rate | 94.8% | 94.6% | 87.4% | 89.1% |
| Arena Elo (AA live) | 1070 | 1011 | 1056 | 993 |
| Time to first audio | 0.81 s | 0.70 s | 1.34 s | 1.35 s |
| AA cost per hour input audio | $4.80 | $4.80 | $5.83 | $3.50 |
| List price | $0.08/min | $0.08/min | $0.05/min plus backend usage | $0.005/min audio in, $0.018/min audio out, plus text tokens |
Benchmark data: Artificial Analysis, accessed October 14, 2026. SpaceXAI’s blog lists frozen Arena Elo values of 1048 (GPT-Live-1) and 990 (Gemini).
How do developers deploy Grok Voice 3.0?
The API is compatible with the OpenAI Realtime API, so migration mostly means a new URL and key.
- Transports: WebSocket, WebRTC demo apps, and SIP for phone and contact-center calls.
- Audio: PCM at 8 to 48 kHz, G.711 μ-law and A-law, and Opus.
- Voices: 28 built-in voices, plus custom voices cloned from a reference clip of up to 120 s.
- Languages: 20 listed locales with automatic language detection.
- Extensions:
force_messagefor scripted lines, pronunciationreplacemaps, and 30-minute session resumption. - Compliance: SOC 2 Type II, HIPAA eligible with a BAA, and GDPR. SpaceXAI says audio is not stored or used for training.
Production teams should pin grok-voice-3.0 rather than the alias. Grok Voice 2.0 is now deprecated.
Key Takeaways
- Grok Voice 3.0 ranks #1 on the AA Speech-to-Speech Index at 86.9.
- It answers in 0.81 s, 40% lower latency than GPT-Live-1 (Astra, medium).
- τ-Voice jumped to 71.6%, but GPT-Live-1 still leads at 74.5%.
- Price stays at $0.08 per minute, and
grok-voice-latestupgraded automatically. - It is API only: no weights, no disclosed size.
Check out the official announcement, the Speech to Speech docs and the Artificial Analysis leaderboard. All credit goes to the researcher of this project. Also, feel free to follow us on Twitter and don’t forget to join our 150k+ML SubReddit and Subscribe to our Newsletter. Wait! are you on telegram? now you can join us on telegram as well.
Michal Sutter is a data science professional with a Master of Science in Data Science from the University of Padova. With a solid foundation in statistical analysis, machine learning, and data engineering, Michal excels at transforming complex datasets into actionable insights.
