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.
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