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.
200k1M
API pricingUSD per 1M tokens · lower wins
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
$5.00—
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.
$25.00—
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.
$0.50—
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.
$5.00Amazon Bedrock—
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$25.00Amazon Bedrock—
$2,250Anthropic list price—
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.
30.8%70%
Overview
CompanyAnthropicMoonshot AI
Release dateNov 24 2025Oct 23 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

Kimi K3.1 Pro leads Claude Opus 4.5 on 1 of the 1 benchmark they both report (Humanity's Last Exam). Only Claude Opus 4.5 has a verified first-party API price: $5.00 per million input tokens and $25.00 per million output tokens. No pay-as-you-go API rate is tracked for Kimi K3.1 Pro. Claude Opus 4.5 shipped 333 days before Kimi K3.1 Pro, so benchmark comparisons should account for the intervening progress.

Context windows are 200k (Claude Opus 4.5) vs 1M (Kimi K3.1 Pro). Claude Opus 4.5 is closed, while Kimi K3.1 Pro is open weight.

On Humanity's Last Exam · with tools, Kimi K3.1 Pro leads at 70% vs Claude Opus 4.5 at 30.8%.