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o1-pro vs Grok 4 Fast

OpenAI o1-pro vs xAI Grok 4 Fast — side-by-side specs.

OpenAI
o1-pro
xAI
Grok 4 Fast
Overview
CompanyOpenAIxAI
Release dateMar 19 2025Sep 2025
Model type
Open sourceNoNo
Specifications
Parameters
Context window
Benchmarks
Science reasoning
GPQA Diamond
Software engineering
SWE-Bench Verified
Multimodal understanding
MMMU
Timeline
Release gapo1-pro shipped 166 days before Grok 4 Fast

Which is better: o1-pro or Grok 4 Fast?

o1-pro and Grok 4 Fast do not have directly comparable benchmark scores published on GPQA Diamond, SWE-Bench Verified, or MMMU. o1-pro shipped 166 days before Grok 4 Fast, 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 o1-pro released?
o1-pro was released by OpenAI on Mar 19 2025.
When was Grok 4 Fast released?
Grok 4 Fast was released by xAI on Sep 2025.

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