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
These models have no shared benchmark scores.
Overview
CompanyAnthropicOpenAI
Release dateMar 4 2024Sep 15 2025
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude 3 Opus and GPT-5-Codex don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude 3 Opus shipped 560 days before GPT-5-Codex, so benchmark comparisons should account for the intervening progress.

Context windows are 200k (Claude 3 Opus) vs 400k (GPT-5-Codex).

Direct benchmark comparisons are unavailable — Claude 3 Opus and GPT-5-Codex don't publish scores on any of the same benchmarks.