AI Model Release Tracker - Timeline of Major AI Models from 2022-2026

o1-pro vs Grok 4 Fast

OpenAI
o1-pro
SpaceXAI
Grok 4 Fast
Overview
CompanyOpenAISpaceXAI
Release dateMar 19 2025Sep 2025
AccessProprietaryProprietary
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 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. 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 — o1-pro and Grok 4 Fast don't publish scores on any of the same benchmarks.

Frequently asked questions

o1-pro was released by OpenAI on Mar 19 2025.

Grok 4 Fast was released by SpaceXAI on Sep 2025.

Other comparisons