What is the difference between Claude Sonnet 5 and GPT-5.1 Codex Max?

Claude Sonnet 5 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 Sonnet 5 or GPT-5.1 Codex Max?

It depends on your use case. Claude Sonnet 5 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 Sonnet 5 and GPT-5.1 Codex Max on Rival?

This page shows a side-by-side comparison of Claude Sonnet 5 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.