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.
2.8T21B
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.
1M128k
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.
—$0.018Darkbloom
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
—$0.09Darkbloom
—$8.10Darkbloom · fp8
Benchmarks
Humanity's Last Exam · with toolsMultidisciplinary reasoning — Humanity's Last Exam — extremely hard expert questions across many subjects. “With tools” means the AI is allowed to search the web or run code while answering. Higher is better.
70%17.3%
Overview
CompanyMoonshot AIOpenAI
Release dateOct 23 2026Aug 5 2025
AccessOpen WeightOpen Weight
Model detailsView modelView model

Frequently asked questions

Kimi K3.1 Pro leads gpt-oss-20b on 1 of the 1 benchmark they both report (Humanity's Last Exam). gpt-oss-20b shipped 444 days before Kimi K3.1 Pro, so benchmark comparisons should account for the intervening progress.

Kimi K3.1 Pro has 2.8T parameters, while gpt-oss-20b has 21B. Context windows are 1M (Kimi K3.1 Pro) vs 128k (gpt-oss-20b).

On Humanity's Last Exam · with tools, Kimi K3.1 Pro leads at 70% vs gpt-oss-20b at 17.3%.