Kimi K2 vs GPT-5.4 mini
Moonshot AI Kimi K2 | OpenAI GPT-5.4 mini | |
|---|---|---|
| Overview | ||
| Company | Moonshot AI | OpenAI |
| Release date | Jul 11 2025 | Mar 17 2026 |
| Access | Open Weight | Proprietary |
| Specifications | ||
Parameters | 1T | — |
Context window | 128k | 400k |
| Benchmarks | ||
Nonsense detection BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | 10% | 32%Best |
Coding SWE-Bench VerifiedReal coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | 65.8% | — |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 75.1% | — |
| Timeline | ||
| Release gap | Kimi K2 shipped 249 days before GPT-5.4 mini | |
Which is better: Kimi K2 or GPT-5.4 mini?
GPT-5.4 mini leads Kimi K2 on 1 of the 1 benchmark they both report (BullshitBench v2). Kimi K2 shipped 249 days before GPT-5.4 mini, so benchmark comparisons should account for the intervening progress.
Context windows are 128k (Kimi K2) vs 400k (GPT-5.4 mini). Kimi K2 is open weight, while GPT-5.4 mini is proprietary.
On BullshitBench v2, GPT-5.4 mini leads at 32% vs Kimi K2 at 10%.
Frequently asked questions
Kimi K2 was released by Moonshot AI on Jul 11 2025.
GPT-5.4 mini was released by OpenAI on Mar 17 2026.
Kimi K2 has a 128k context window; GPT-5.4 mini has 400k.
Kimi K2 is an open weight model released by Moonshot AI. GPT-5.4 mini is a proprietary model released by OpenAI.
Other comparisons
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