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. | — | 256k |
| API pricingUSD per 1M tokens · lower wins | ||
Cheapest inputLowest input rate across third-party providers, excluding the lab itself. 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 third-party providers, excluding the lab itself. May come from a different provider than the cheapest input. | — | $2.50Novita |
| Benchmarks | ||
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. | 49% | 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 | Oct 22 2024 | Sep 5 2025 |
| Access | Closed | Open Weight |
| Model details | View model | View model |
Other comparisons
Claude 3.5 Sonnet (upgraded)vsGPT-6.1 SolKimi K2 (0905)vsGPT-6.1 SolClaude 3.5 Sonnet (upgraded)vsGemini 4 ArgonKimi K2 (0905)vsGemini 4 ArgonClaude 3.5 Sonnet (upgraded)vsMuse Spark 1.3Kimi K2 (0905)vsMuse Spark 1.3Claude 3.5 Sonnet (upgraded)vsGrok 4.7Kimi K2 (0905)vsGrok 4.7Claude 3.5 Sonnet (upgraded)vsDeepSeek-V4.1-FlashKimi K2 (0905)vsDeepSeek-V4.1-FlashClaude 3.5 Sonnet (upgraded)vsMistral Large 4Kimi K2 (0905)vsMistral Large 4Frequently asked questions
Kimi K2 (0905) leads Claude 3.5 Sonnet (upgraded) on 1 of the 1 benchmark they both report (SWE-Bench Verified). Claude 3.5 Sonnet (upgraded) shipped 318 days before Kimi K2 (0905), so benchmark comparisons should account for the intervening progress.
Claude 3.5 Sonnet (upgraded) is closed, while Kimi K2 (0905) is open weight.
On SWE-Bench Verified, Kimi K2 (0905) leads at 65.8% vs Claude 3.5 Sonnet (upgraded) at 49%.