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

Kimi K2 (0905) vs GPT-5-Codex-Mini

Moonshot AI
Kimi K2 (0905)
OpenAI
GPT-5-Codex-Mini
Overview
CompanyMoonshot AIOpenAI
Release dateSep 5 2025Nov 8 2025
AccessOpen WeightProprietary
Specifications
Parameters
1T
Context window
256k
Benchmarks
Coding
SWE-Bench Verified
65.8%
Science
GPQA Diamond
75.1%
Timeline
Release gapKimi K2 (0905) shipped 64 days before GPT-5-Codex-Mini

Which is better: Kimi K2 (0905) or GPT-5-Codex-Mini?

Kimi K2 (0905) and GPT-5-Codex-Mini don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Kimi K2 (0905) shipped 64 days before GPT-5-Codex-Mini, so benchmark comparisons should account for the intervening progress.

Kimi K2 (0905) is open weight, while GPT-5-Codex-Mini is proprietary.

Direct benchmark comparisons are unavailable — Kimi K2 (0905) and GPT-5-Codex-Mini 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.

GPT-5-Codex-Mini was released by OpenAI on Nov 8 2025.

Kimi K2 (0905) is an open weight model released by Moonshot AI. GPT-5-Codex-Mini is a proprietary model released by OpenAI.

Other comparisons