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xAI

Grok 4 Fast

Release page →
xAI

Grok 4.1

Release page →

The basics

Released

Sep 19, 2025
Nov 17, 2025

What it does

Text and chat: Writes, answers questions and holds a conversation.Code: Writes, explains and fixes code.Thinks first: Can reason step by step before it answers: slower, but better at maths, code and tricky questions.
Text and chat: Writes, answers questions and holds a conversation.Code: Writes, explains and fixes code.Thinks first: Can reason step by step before it answers: slower, but better at maths, code and tricky questions.

Knowledge cutoff

The latest events it learned about

Not published
Not published

Download

No: it runs on the maker's servers
No: it runs on the maker's servers

Where to use it

xAI's app: Grok ↗Also for developers, through an API
xAI's app: Grok ↗Also for developers, through an API

How they score

Combined test score

Epoch Capabilities Index · Epoch AI

144#97 of 237
Not ranked

Only Grok 4 Fast is in this ranking.

Chat answers, by people's votes

LMArena text, adjusted for style · LMArena

Not ranked
1,465#47 of 86

Only Grok 4.1 is in this ranking, which lists the most-voted models.

Green marks the better of the two on each row, red the other. Rows where one side isn't listed, or where the gap is too close to call, stay plain.

Popular comparisons

Not sure where to start? Which AI should I use? gives a pick for what you want to do. How to read AI rankings explains the numbers.

Rankings from LMArena and Epoch AI, both CC BY 4.0, updated . Developer prices, context windows and knowledge cutoffs from the labs' own listings on models.dev and from OpenRouter. The app links go to each maker's own app when no source says exactly where the model is available.

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