Kimi K2 vs Grok 4.5
Moonshot AI Kimi K2 | SpaceXAI Grok 4.5 | |
|---|---|---|
| Overview | ||
| Company | Moonshot AI | SpaceXAI |
| Release date | Jul 11 2025 | Jul 8 2026 |
| Access | Open Weight | Proprietary |
| Specifications | ||
Parameters | 1T | — |
Context window | 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% | — |
Agentic coding SWE-Bench ProCan the AI fix real bugs in real software? It's handed actual problems from open-source projects and has to write code that genuinely solves them. Higher is better. | — | 64.7% |
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% | — |
Multilingual coding SWE-Bench MultilingualLike SWE-Bench, but the coding problems span many programming languages, not just one. Tests how broadly the AI can code. Higher is better. | — | 78% |
Agentic coding DeepSWE 1.0Artificial Analysis' independent test of deep, agentic software-engineering work — the AI has to plan and carry out substantial coding tasks end to end. Higher is better. | — | 62% |
Agentic terminal coding Terminal-Bench 2.1Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Higher is better. | — | 83.3% |
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 362 days before Grok 4.5 | |
Which is better: Kimi K2 or Grok 4.5?
Kimi K2 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 shipped 362 days before Grok 4.5, so benchmark comparisons should account for the intervening progress.
Kimi K2 is open weight, while Grok 4.5 is proprietary.
Direct benchmark comparisons are unavailable — Kimi K2 and Grok 4.5 don't publish scores on any of the same benchmarks.
Frequently asked questions
Kimi K2 was released by Moonshot AI on Jul 11 2025.
Grok 4.5 was released by SpaceXAI on Jul 8 2026.
Kimi K2 is an open weight model released by Moonshot AI. Grok 4.5 is a proprietary model released by SpaceXAI.