What is the difference between GPT-4o (Omni) and Grok 4.1 Fast?

GPT-4o (Omni) is developed by OpenAI while Grok 4.1 Fast is developed by xAI. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, GPT-4o (Omni) or Grok 4.1 Fast?

It depends on your use case. GPT-4o (Omni) and Grok 4.1 Fast 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 GPT-4o (Omni) and Grok 4.1 Fast on Rival?

This page shows a side-by-side comparison of GPT-4o (Omni) 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.

What is the difference between GPT-4o (Omni) and Grok 4.1 Fast?

GPT-4o (Omni) is developed by OpenAI while Grok 4.1 Fast is developed by xAI. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, GPT-4o (Omni) or Grok 4.1 Fast?

It depends on your use case. GPT-4o (Omni) and Grok 4.1 Fast 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 GPT-4o (Omni) and Grok 4.1 Fast on Rival?

This page shows a side-by-side comparison of GPT-4o (Omni) 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.

GPT-4o (Omni) vs Grok 4.1 Fast: Which Is Better?

Updated Nov 2025

Our Verdict

GPT-4o (Omni)

Grok 4.1 Fast

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call

API pricing

Cost per 1M tokens

GPT-4o (Omni)

Input

$2.50

Output

$10.00

Grok 4.1 Fast

Input

—

Output

—

Writing DNA

Style Comparison

Similarity

33%

GPT-4o (Omni) uses 2.5x more emoji

GPT-4o (Omni)

Grok 4.1 Fast

54%Vocabulary67%

18wSentence Length15w

0.72Hedging0.17

7.3Bold4.7

5.6Lists3.7

0.03Emoji0.00

1.40Headings0.99

0.26Transitions0.14

Based on 24 + 24 text responses

Research

What we learned reading every model

GPT-4o (Omni) and Grok 4.1 Fast 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

GPT-4o (Omni) vs MiniMax M3New provider

GPT-4o (Omni) vs Llama 4 MaverickNew provider

Grok 4.1 Fast vs GPT-5Cross-provider

Updated Nov 2025

Our Verdict

GPT-4o (Omni)

Grok 4.1 Fast

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call

API pricing

Cost per 1M tokens

GPT-4o (Omni)

Input

$2.50

Output

$10.00

Grok 4.1 Fast

Input

—

Output

—

Writing DNA

Style Comparison

Similarity

33%

GPT-4o (Omni) uses 2.5x more emoji

GPT-4o (Omni)

Grok 4.1 Fast

54%Vocabulary67%

18wSentence Length15w

0.72Hedging0.17

7.3Bold4.7

5.6Lists3.7

0.03Emoji0.00

1.40Headings0.99

0.26Transitions0.14

Based on 24 + 24 text responses

Research

What we learned reading every model

GPT-4o (Omni) and Grok 4.1 Fast 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

GPT-4o (Omni) vs MiniMax M3New provider

GPT-4o (Omni) vs Llama 4 MaverickNew provider

Grok 4.1 Fast vs GPT-5Cross-provider