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

Kimi K2 (0905) vs Grok 4.5

Moonshot AI
Kimi K2 (0905)
SpaceXAI
Grok 4.5
Overview
CompanyMoonshot AISpaceXAI
Release dateSep 5 2025Jul 8 2026
AccessOpen WeightProprietary
Specifications
Parameters
1T
Context window
256k
Benchmarks
Agentic coding
SWE-Bench Pro
64.7%
Coding
SWE-Bench Verified
65.8%
Multilingual coding
SWE-Bench Multilingual
78%
Agentic coding
DeepSWE 1.0
62%
Agentic terminal coding
Terminal-Bench 2.1
83.3%
Science
GPQA Diamond
75.1%
Timeline
Release gapKimi K2 (0905) shipped 306 days before Grok 4.5

Which is better: Kimi K2 (0905) or Grok 4.5?

Kimi K2 (0905) and Grok 4.5 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Kimi K2 (0905) shipped 306 days before Grok 4.5, so benchmark comparisons should account for the intervening progress.

Kimi K2 (0905) is open weight, while Grok 4.5 is proprietary.

Direct benchmark comparisons are unavailable — Kimi K2 (0905) and Grok 4.5 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 4.5 was released by SpaceXAI on Jul 8 2026.

Kimi K2 (0905) is an open weight model released by Moonshot AI. Grok 4.5 is a proprietary model released by SpaceXAI.

Other comparisons