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

GPT-5.6 Terra vs Grok 4 Heavy

OpenAI
GPT-5.6 Terra
SpaceXAI
Grok 4 Heavy
Overview
CompanyOpenAISpaceXAI
Release dateJun 26 2026Jul 9 2025
AccessProprietaryProprietary
Benchmarks
Nonsense detection
BullshitBench v2
53%
Agentic terminal coding
Terminal-Bench 2.1
84.3%
Timeline
Release gapGrok 4 Heavy shipped 352 days before GPT-5.6 Terra

Which is better: GPT-5.6 Terra or Grok 4 Heavy?

GPT-5.6 Terra 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 352 days before GPT-5.6 Terra, 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 — GPT-5.6 Terra and Grok 4 Heavy don't publish scores on any of the same benchmarks.

Frequently asked questions

GPT-5.6 Terra was released by OpenAI on Jun 26 2026.

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

Other comparisons