Compare AI models

Specifications
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.
200k—
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.
$3.00—
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.
$15.00—
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.
$0.30—
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.
$3.00Amazon Bedrock—
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$15.00Amazon Bedrock—
$1,350Anthropic list price—
Benchmarks
Next.js EvalsNext.js coding — Vercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better.
36%57%
Terminal-Bench 2.0Agentic terminal coding — Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? (Version 2.0 of the test.) Higher is better.
51%61.7%
Overview
CompanyAnthropicSpaceXSI
Release dateSep 29 2025Mar 19 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Composer 2 leads Claude Sonnet 4.5 on 2 of the 2 benchmarks they both report (Next.js Evals, Terminal-Bench 2.0). Only Claude Sonnet 4.5 has a verified first-party price for an available API: $3.00 per million input tokens and $15.00 per million output tokens. No currently available pay-as-you-go API rate is tracked for Composer 2. Claude Sonnet 4.5 shipped 171 days before Composer 2, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

On Next.js Evals, Composer 2 leads at 57% vs Claude Sonnet 4.5 at 36%. On Terminal-Bench 2.0, Composer 2 leads at 61.7% vs Claude Sonnet 4.5 at 51%.