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

Kimi K2 Thinking vs Grok 4 Heavy

Moonshot AI
Kimi K2 Thinking
SpaceXAI
Grok 4 Heavy
Overview
CompanyMoonshot AISpaceXAI
Release dateNov 6 2025Jul 9 2025
AccessOpen WeightProprietary
Specifications
Parameters
1T
Context window
256k
Benchmarks
Coding
SWE-Bench Verified
71.3%
Timeline
Release gapGrok 4 Heavy shipped 120 days before Kimi K2 Thinking

Which is better: Kimi K2 Thinking or Grok 4 Heavy?

Kimi K2 Thinking 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 120 days before Kimi K2 Thinking, so benchmark comparisons should account for the intervening progress.

Kimi K2 Thinking is open weight, while Grok 4 Heavy is proprietary.

Direct benchmark comparisons are unavailable — Kimi K2 Thinking and Grok 4 Heavy don't publish scores on any of the same benchmarks.

Frequently asked questions

Kimi K2 Thinking was released by Moonshot AI on Nov 6 2025.

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

Kimi K2 Thinking is an open weight model released by Moonshot AI. Grok 4 Heavy is a proprietary model released by SpaceXAI.

Other comparisons