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.
200k400k
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.
—$1.25Azure
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
—$10.00Azure
—$750Azure
These models have no shared benchmark scores.
Overview
CompanyAnthropicOpenAI
Release dateMar 4 2024Nov 19 2025
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude 3 Opus and GPT-5.1-Codex-Max don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude 3 Opus shipped 625 days before GPT-5.1-Codex-Max, so benchmark comparisons should account for the intervening progress.

Context windows are 200k (Claude 3 Opus) vs 400k (GPT-5.1-Codex-Max).

Direct benchmark comparisons are unavailable — Claude 3 Opus and GPT-5.1-Codex-Max don't publish scores on any of the same benchmarks.