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.
2.8T—
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.
1M1.05M
API pricingUSD per 1M tokens · lower wins · base tier
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
—$10.00
Output priceWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one.
—$50.00
Cached input priceA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again.
—$1.00
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.
—$5.00OpenAI
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
—$25.00OpenAI
—$4,500OpenAI list price
Benchmarks
BenchCADCAD programming — Can the AI do mechanical design as code? Given a drawing or a description of an industrial part — a gear, a spring, a drill bit — it has to write or edit the parametric CAD program that builds it, and the program is run to check the shape really comes out right. Higher is better.
92.7%95.9%
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.
65.7%57.9%
Terminal-Bench-Science 0.1Agentic scientific computing — The same command-line setup as Terminal-Bench, pointed at scientific work: the AI has to drive research tooling and computational workflows through to a result, rather than administer a machine. Version 0.1 is the first release of the task set, and scores run lower than on the general board. Higher is better.
38.1%64.6%
Overview
CompanyMoonshot AIOpenAI
Release dateOct 23 2026Sep 3 2026
AccessOpen WeightClosed
Model detailsView modelView model

Frequently asked questions

GPT-6 Astra leads Kimi K3.1 Pro on 2 of the 3 benchmarks they both report (BenchCAD, Terminal-Bench 4.0, Terminal-Bench-Science 0.1). Only GPT-6 Astra has a verified first-party API price: $10.00 per million input tokens and $50.00 per million output tokens. No pay-as-you-go API rate is tracked for Kimi K3.1 Pro. GPT-6 Astra shipped 50 days before Kimi K3.1 Pro, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Kimi K3.1 Pro) vs 1.05M (GPT-6 Astra). Kimi K3.1 Pro is open weight, while GPT-6 Astra is closed.

On BenchCAD, GPT-6 Astra leads at 95.9% vs Kimi K3.1 Pro at 92.7%. On Terminal-Bench 4.0, Kimi K3.1 Pro leads at 65.7% vs GPT-6 Astra at 57.9%. On Terminal-Bench-Science 0.1, GPT-6 Astra leads at 64.6% vs Kimi K3.1 Pro at 38.1%.