What is the difference between Grok 4.1 Fast and OpenAI o4-mini?

Grok 4.1 Fast is developed by xAI while OpenAI o4-mini is developed by OpenAI. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Grok 4.1 Fast or OpenAI o4-mini?

It depends on your use case. Grok 4.1 Fast and OpenAI o4-mini each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.

How can I compare Grok 4.1 Fast and OpenAI o4-mini on Rival?

This page shows a side-by-side comparison of Grok 4.1 Fast and OpenAI o4-mini 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.

What is the difference between Grok 4.1 Fast and OpenAI o4-mini?

Grok 4.1 Fast is developed by xAI while OpenAI o4-mini is developed by OpenAI. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Grok 4.1 Fast or OpenAI o4-mini?

It depends on your use case. Grok 4.1 Fast and OpenAI o4-mini each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.

How can I compare Grok 4.1 Fast and OpenAI o4-mini on Rival?

This page shows a side-by-side comparison of Grok 4.1 Fast and OpenAI o4-mini 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.

Grok 4.1 Fast vs OpenAI o4-mini: Which Is Better?

Updated Nov 2025

Our Verdict

Grok 4.1 Fast

OpenAI o4-miniRunner-up

No community votes yet. On paper, Grok 4.1 Fast has the edge — bigger model tier, newer.

Too close to call

API pricing

Cost per 1M tokens

Grok 4.1 Fast

Input

—

Output

—

OpenAI o4-mini

Input

$1.10

Output

$4.40

Writing DNA

Style Comparison

Similarity

52%

Grok 4.1 Fast uses 466.5x more bold

Grok 4.1 Fast

OpenAI o4-mini

67%Vocabulary73%

15wSentence Length15w

0.17Hedging0.18

4.7Bold0.0

3.7Lists2.1

0.00Emoji0.00

0.99Headings0.00

0.14Transitions0.02

Based on 24 + 10 text responses

Research

What we learned reading every model

Grok 4.1 Fast and OpenAI o4-mini have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

More comparisons

OpenAI o4-mini vs MiniMax M3New provider

Grok 4.1 Fast vs Llama 4 MaverickNew provider

Grok 4.1 Fast vs Gemini 2.5 Pro (I/O Edition)New provider

Updated Nov 2025

Our Verdict

Grok 4.1 Fast

OpenAI o4-miniRunner-up

No community votes yet. On paper, Grok 4.1 Fast has the edge — bigger model tier, newer.

Too close to call

API pricing

Cost per 1M tokens

Grok 4.1 Fast

Input

—

Output

—

OpenAI o4-mini

Input

$1.10

Output

$4.40

Writing DNA

Style Comparison

Similarity

52%

Grok 4.1 Fast uses 466.5x more bold

Grok 4.1 Fast

OpenAI o4-mini

67%Vocabulary73%

15wSentence Length15w

0.17Hedging0.18

4.7Bold0.0

3.7Lists2.1

0.00Emoji0.00

0.99Headings0.00

0.14Transitions0.02

Based on 24 + 10 text responses

Research

What we learned reading every model

Grok 4.1 Fast and OpenAI o4-mini have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

More comparisons

OpenAI o4-mini vs MiniMax M3New provider

Grok 4.1 Fast vs Llama 4 MaverickNew provider

Grok 4.1 Fast vs Gemini 2.5 Pro (I/O Edition)New provider