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Gemini 3.1 Pro vs Grok 4 Fast

2 vs 0 benchmarks won

Google
Gemini 3.1 Pro
xAI
Grok 4 Fast
Overview
CompanyGooglexAI
Release dateFeb 19 2026Sep 2025
Model type
Open sourceNoNo
Specifications
Parameters
Context window
Benchmarks
Science reasoning
GPQA Diamond
94.3%
Software engineering
SWE-Bench Verified
80.6%
Multimodal understanding
MMMU
Timeline
Release gapGrok 4 Fast shipped 171 days before Gemini 3.1 Pro

Which is better: Gemini 3.1 Pro or Grok 4 Fast?

Gemini 3.1 Pro leads Grok 4 Fast on 2 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). Grok 4 Fast shipped 171 days before Gemini 3.1 Pro, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

Direct benchmark comparisons are unavailable — at least one of these models has not published scores on GPQA Diamond, SWE-Bench Verified, or MMMU.

Frequently asked questions

When was Gemini 3.1 Pro released?
Gemini 3.1 Pro was released by Google on Feb 19 2026.
When was Grok 4 Fast released?
Grok 4 Fast was released by xAI on Sep 2025.

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