What is the difference between Claude Opus 4.5 and OpenAI o3?

Claude Opus 4.5 is developed by Anthropic while OpenAI o3 is developed by OpenAI. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4.5 or OpenAI o3?

It depends on your use case. Claude Opus 4.5 and OpenAI o3 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.

How can I compare Claude Opus 4.5 and OpenAI o3 on Rival?

This page shows a side-by-side comparison of Claude Opus 4.5 and OpenAI o3 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.