What is the difference between Claude Opus 4 and GPT-5.1?

Claude Opus 4 is developed by Anthropic while GPT-5.1 is developed by OpenAI. Claude Opus 4 has a 200K token context window vs GPT-5.1's 400K. You can compare their actual outputs across 51 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4 or GPT-5.1?

It depends on your use case. Claude Opus 4 and GPT-5.1 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 51 challenges so you can judge which fits your needs best.

How much does Claude Opus 4 cost compared to GPT-5.1?

Claude Opus 4 costs $15/M input tokens and GPT-5.1 costs $1.25/M input tokens. GPT-5.1 is $13.75/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare Claude Opus 4 and GPT-5.1 on Rival?

This page shows a side-by-side comparison of Claude Opus 4 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 4vsGPT-5.1

GPT-5.1 is cheaper than Claude Opus 4 at $1.25/M vs $15/M input tokens.

Claude Opus 4 and GPT-5.1 compared across 51 shared prompts
Spec	Claude Opus 4	GPT-5.1
Input price	$15/M tokens	$1.25/M tokens
Output price	$75/M tokens	$10/M tokens
Context window	200K tokens	400K tokens
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	May 2025	Nov 2025
SWE-bench Verified	72.5%	76.3%