Compare AI models
| Specifications | ||
ParametersA rough measure of how big the model is. More parameters usually means more capable and more expensive to run, though it is a poor guide on its own — a smaller, newer model often beats a larger, older one. | — | 1T |
Context windowHow much text the model can hold in mind at once — your question, any documents you attach, the conversation so far, and its own reply. Go past it and the earliest part falls out of view. | 200k | 256k |
| API pricingUSD per 1M tokens · lower wins | ||
Cheapest inputLowest input rate across every provider on OpenRouter, the lab included. The cheapest endpoint may run a quantised build or a shorter context — see "Available from" on the model page. | — | $0.60Novita |
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input. | — | $2.50Novita |
| — | $245Novita · fp8 | |
| These models have no shared benchmark scores. | ||
SWE-Bench VerifiedCoding — Real 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% |
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | — | 75.1% |
| Overview | ||
| Company | Anthropic | Moonshot AI |
| Release date | Nov 21 2023 | Sep 5 2025 |
| Access | Closed | Open Weight |
| Model details | View model | View model |
Other comparisons
Claude 2.1vsGPT-6.1 SolKimi K2 (0905)vsGPT-6.1 SolClaude 2.1vsGemini 4 ArgonKimi K2 (0905)vsGemini 4 ArgonClaude 2.1vsMuse WonderKimi K2 (0905)vsMuse WonderClaude 2.1vsGrok 4.7Kimi K2 (0905)vsGrok 4.7Claude 2.1vsDeepSeek-V4.1-FlashKimi K2 (0905)vsDeepSeek-V4.1-FlashClaude 2.1vsMistral Large 4Kimi K2 (0905)vsMistral Large 4Frequently asked questions
Claude 2.1 and Kimi K2 (0905) don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude 2.1 shipped 654 days before Kimi K2 (0905), so benchmark comparisons should account for the intervening progress.
Context windows are 200k (Claude 2.1) vs 256k (Kimi K2 (0905)). Claude 2.1 is closed, while Kimi K2 (0905) is open weight.
Direct benchmark comparisons are unavailable — Claude 2.1 and Kimi K2 (0905) don't publish scores on any of the same benchmarks.