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

Grok 2.5 vs Grok 4 Heavy

SpaceXAI
Grok 2.5
SpaceXAI
Grok 4 Heavy
Overview
CompanySpaceXAISpaceXAI
Release dateAug 2025Jul 9 2025
AccessProprietaryProprietary
Timeline
Release gapGrok 4 Heavy shipped 23 days before Grok 2.5

Which is better: Grok 2.5 or Grok 4 Heavy?

Grok 2.5 and Grok 4 Heavy don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Grok 4 Heavy shipped 23 days before Grok 2.5, 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 — Grok 2.5 and Grok 4 Heavy don't publish scores on any of the same benchmarks.

Frequently asked questions

Grok 2.5 was released by SpaceXAI on Aug 2025.

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

Other comparisons