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. | 9k | 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 | Mar 14 2023 | Sep 5 2025 |
| Access | Closed | Open Weight |
| Model details | View model | View model |
Other comparisons
Claude 1vsGPT-6.1 SolKimi K2 (0905)vsGPT-6.1 SolClaude 1vsGemini 4 ArgonKimi K2 (0905)vsGemini 4 ArgonClaude 1vsMuse WonderKimi K2 (0905)vsMuse WonderClaude 1vsGrok 4.7Kimi K2 (0905)vsGrok 4.7Claude 1vsDeepSeek-V4.1-FlashKimi K2 (0905)vsDeepSeek-V4.1-FlashClaude 1vsMistral Large 4Kimi K2 (0905)vsMistral Large 4Frequently asked questions
Claude 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 1 shipped 906 days before Kimi K2 (0905), so benchmark comparisons should account for the intervening progress.
Context windows are 9k (Claude 1) vs 256k (Kimi K2 (0905)). Claude 1 is closed, while Kimi K2 (0905) is open weight.
Direct benchmark comparisons are unavailable — Claude 1 and Kimi K2 (0905) don't publish scores on any of the same benchmarks.