What is the difference between Claude Opus 4.5 and GPT-5.1?

Claude Opus 4.5 is developed by Anthropic while GPT-5.1 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 4.5 or GPT-5.1?

It depends on your use case. Claude Opus 4.5 and GPT-5.1 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 4.5 and GPT-5.1 on Rival?

This page shows a side-by-side comparison of Claude Opus 4.5 and GPT-5.1 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 Nov 2025

Claude Opus 4.5vsGPT-5.1

Claude Opus 4.5 is the newer model, released after GPT-5.1.

Claude Opus 4.5 and GPT-5.1 compared across 52 shared prompts
Spec	Claude Opus 4.5	GPT-5.1
Input price	—	$1.25/M tokens
Output price	—	$10/M tokens
Context window	—	400K tokens
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	Nov 2025	Nov 2025
SWE-bench Verified	80.9%	76.3%