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

Kimi K2 (0905) vs Grok 4

Moonshot AI
Kimi K2 (0905)
SpaceXAI
Grok 4
Overview
CompanyMoonshot AISpaceXAI
Release dateSep 5 2025Jul 9 2025
AccessOpen WeightProprietary
Specifications
Parameters
1T
Context window
256k
Benchmarks
Coding
SWE-Bench Verified
65.8%
Science
GPQA Diamond
75.1%
Timeline
Release gapGrok 4 shipped 58 days before Kimi K2 (0905)

Which is better: Kimi K2 (0905) or Grok 4?

Kimi K2 (0905) and Grok 4 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Grok 4 shipped 58 days before Kimi K2 (0905), so benchmark comparisons should account for the intervening progress.

Kimi K2 (0905) is open weight, while Grok 4 is proprietary.

Direct benchmark comparisons are unavailable — Kimi K2 (0905) and Grok 4 don't publish scores on any of the same benchmarks.

Frequently asked questions

Kimi K2 (0905) was released by Moonshot AI on Sep 5 2025.

Grok 4 was released by SpaceXAI on Jul 9 2025.

Kimi K2 (0905) is an open weight model released by Moonshot AI. Grok 4 is a proprietary model released by SpaceXAI.

Other comparisons