Mistral Medium 3.5vsKimi K2
Mistral Medium 3.5 | Kimi K2 | |
|---|---|---|
| Specifications | ||
Parameters | 128B | 1T |
Context window | 256k | 128k |
| 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% |
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. | 77.6%Best | 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% |
Community preference (code) Arena Elo (Code)Like the text arena, but people vote on which AI writes better code. The votes become a chess-style Elo rating on arena.ai. Higher is better. | 1267 | — |
| Overview | ||
| Company | Mistral | Moonshot AI |
| Release date | Apr 29 2026 | Jul 11 2025 |
| Access | Open Weight | Open Weight |
Which is better: Mistral Medium 3.5 or Kimi K2?
Mistral Medium 3.5 leads Kimi K2 on 1 of the 1 benchmark they both report (SWE-Bench Verified). Kimi K2 shipped 292 days before Mistral Medium 3.5, so benchmark comparisons should account for the intervening progress.
Mistral Medium 3.5 has 128B parameters, while Kimi K2 has 1T. Context windows are 256k (Mistral Medium 3.5) vs 128k (Kimi K2).
On SWE-Bench Verified, Mistral Medium 3.5 leads at 77.6% vs Kimi K2 at 65.8%.
Frequently asked questions
Mistral Medium 3.5 was released by Mistral on Apr 29 2026.
Kimi K2 was released by Moonshot AI on Jul 11 2025.
Mistral Medium 3.5 leads on SWE-Bench Verified — Mistral Medium 3.5 77.6% vs Kimi K2 65.8%.
Mistral Medium 3.5 has a 256k context window; Kimi K2 has 128k.
Other comparisons
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