Compare AI models
| Specifications | ||
ParametersThe learned values that shape how a model responds. B means billion and T means trillion. For mixture-of-experts models, the total count is larger than the number active for each token. Parameter count alone does not measure quality. | 1T | — |
Context windowHow much information the model can work with in one request, measured in tokens — pieces of words or other data. This includes your question, attachments, conversation and reply. Limits can vary by model variant and provider. | 256k | 2M |
| 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 | Moonshot AI | SpaceXSI |
| Release date | Sep 5 2025 | Sep 19 2025 |
| Access | Open Weight | Closed |
| Model details | View model | View model |
Other comparisons
Kimi K2 (0905)vsClaude Haiku 5.5Grok 4 FastvsClaude Haiku 5.5Kimi K2 (0905)vsGPT-6.1 SolGrok 4 FastvsGPT-6.1 SolKimi K2 (0905)vsGemini 4 ArgonGrok 4 FastvsGemini 4 ArgonKimi K2 (0905)vsMuse Spark OpenGrok 4 FastvsMuse Spark OpenKimi K2 (0905)vsDeepSeek-V4.1-Flash-1017Grok 4 FastvsDeepSeek-V4.1-Flash-1017Kimi K2 (0905)vsMistral Large 4Grok 4 FastvsMistral Large 4Frequently asked questions
Kimi K2 (0905) and Grok 4 Fast don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Kimi K2 (0905) shipped 14 days before Grok 4 Fast, so benchmark comparisons should account for the intervening progress.
Context windows are 256k (Kimi K2 (0905)) vs 2M (Grok 4 Fast). Kimi K2 (0905) is open weight, while Grok 4 Fast is closed.
Direct benchmark comparisons are unavailable — Kimi K2 (0905) and Grok 4 Fast don't publish scores on any of the same benchmarks.