What is the difference between GPT-5 and GPT-5.1?

Both are developed by OpenAI but target different use cases. GPT-5 has a 400K 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, GPT-5 or GPT-5.1?

It depends on your use case. GPT-5 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 GPT-5 cost compared to GPT-5.1?

GPT-5 costs $1.25/M input tokens and GPT-5.1 costs $1.25/M input tokens. GPT-5.1 is $0.00/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 GPT-5 and GPT-5.1 on Rival?

This page shows a side-by-side comparison of GPT-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

GPT-5vsGPT-5.1

GPT-5.1 is the newer model, released after GPT-5.

GPT-5 and GPT-5.1 compared across 51 shared prompts
Spec	GPT-5	GPT-5.1
Input price	$1.25/M tokens	$1.25/M tokens
Output price	$10/M tokens	$10/M tokens
Context window	400K tokens	400K tokens
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	Aug 2025	Nov 2025
SWE-bench Verified	74.9%	76.3%