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. | 1M | 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. | — | $0.60Google |
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input. | — | $2.50Google |
| — | $245Novita · bf16 | |
| 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. | — | 71.3% |
Terminal-Bench 4.0Agentic terminal coding — Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Version 4.0 recalibrated how much time, CPU and memory each task gets, removed eight tasks and fixed nineteen, so fewer runs fail for reasons that have nothing to do with the model. Scores are not comparable with earlier versions. Higher is better. | 60.9% | — |
| Overview | ||
| Company | Anthropic | Moonshot AI |
| Release date | Sep 1 2026 | Nov 6 2025 |
| Access | Closed | Open Weight |
| Model details | View model | View model |
Other comparisons
Claude Mythos 5.1vsGPT-6.1 SolKimi K2 ThinkingvsGPT-6.1 SolClaude Mythos 5.1vsGemini 4 ArgonKimi K2 ThinkingvsGemini 4 ArgonClaude Mythos 5.1vsMuse Spark OpenKimi K2 ThinkingvsMuse Spark OpenClaude Mythos 5.1vsGrok 4.7Kimi K2 ThinkingvsGrok 4.7Claude Mythos 5.1vsDeepSeek-V4.1-FlashKimi K2 ThinkingvsDeepSeek-V4.1-FlashClaude Mythos 5.1vsMistral Large 4Kimi K2 ThinkingvsMistral Large 4Frequently asked questions
Claude Mythos 5.1 and Kimi K2 Thinking don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Kimi K2 Thinking shipped 299 days before Claude Mythos 5.1, so benchmark comparisons should account for the intervening progress.
Context windows are 1M (Claude Mythos 5.1) vs 256k (Kimi K2 Thinking). Claude Mythos 5.1 is closed, while Kimi K2 Thinking is open weight.
Direct benchmark comparisons are unavailable — Claude Mythos 5.1 and Kimi K2 Thinking don't publish scores on any of the same benchmarks.