What is the difference between Claude Opus 4.1 and GPT-5.1 Codex Max?

Claude Opus 4.1 is developed by Anthropic while GPT-5.1 Codex Max is developed by OpenAI. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4.1 or GPT-5.1 Codex Max?

It depends on your use case. Claude Opus 4.1 and GPT-5.1 Codex Max each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.

How can I compare Claude Opus 4.1 and GPT-5.1 Codex Max on Rival?

This page shows a side-by-side comparison of Claude Opus 4.1 and GPT-5.1 Codex Max across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

Updated Dec 2025

Claude Opus 4.1vsGPT-5.1 Codex Max

GPT-5.1 Codex Max is the newer model, released after Claude Opus 4.1.

Claude Opus 4.1 and GPT-5.1 Codex Max compared across 52 shared prompts
Spec	Claude Opus 4.1	GPT-5.1 Codex Max
Input price	$15/M tokens	—
Output price	$75/M tokens	—
Context window	200K tokens	—
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	Aug 2025	Dec 2025
SWE-bench Verified	74.5%	77.9%