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

o4-mini vs Grok 4 Heavy

OpenAI
o4-mini
SpaceXAI
Grok 4 Heavy
Overview
CompanyOpenAISpaceXAI
Release dateApr 16 2025Jul 9 2025
AccessProprietaryProprietary
Benchmarks
Nonsense detection
BullshitBench v2
8%
Timeline
Release gapo4-mini shipped 84 days before Grok 4 Heavy

Which is better: o4-mini or Grok 4 Heavy?

o4-mini and Grok 4 Heavy don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. o4-mini shipped 84 days before Grok 4 Heavy, 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 — o4-mini and Grok 4 Heavy don't publish scores on any of the same benchmarks.

Frequently asked questions

o4-mini was released by OpenAI on Apr 16 2025.

Grok 4 Heavy was released by SpaceXAI on Jul 9 2025.

Other comparisons