What is the difference between GPT-5.1 and Grok 4.1 Fast?

GPT-5.1 is developed by OpenAI while Grok 4.1 Fast is developed by xAI. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 or Grok 4.1 Fast?

It depends on your use case. GPT-5.1 and Grok 4.1 Fast 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 GPT-5.1 and Grok 4.1 Fast on Rival?

This page shows a side-by-side comparison of GPT-5.1 and Grok 4.1 Fast 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.