What is the difference between GPT-4o (Omni) and xAI: Grok 4?

GPT-4o (Omni) is developed by OpenAI while xAI: Grok 4 is developed by xAI. GPT-4o (Omni) has a 128K token context window vs xAI: Grok 4's 256K. These results are based on blind head-to-head voting across 53 challenges.

Which is better, GPT-4o (Omni) or xAI: Grok 4?

Based on 2 community votes on Rival, GPT-4o (Omni) and xAI: Grok 4 are closely matched with similar win rates. The better choice depends on your specific use case. Compare their real outputs side-by-side across 53 challenges to decide.

How much does GPT-4o (Omni) cost compared to xAI: Grok 4?

GPT-4o (Omni) costs $2.5/M input tokens and xAI: Grok 4 costs $3/M input tokens. GPT-4o (Omni) is $0.50/M cheaper per input. The more expensive model wins 50% of duels, so the premium may be justified by quality.

How are GPT-4o (Omni) vs xAI: Grok 4 votes collected on Rival?

Rival presents both models' outputs side-by-side in blind duels. Voters see the responses but don't know which model produced each one, eliminating brand bias. 2 votes have been collected for this pair across 53 challenges. All vote data is part of Rival's open dataset.

What is the difference between GPT-4o (Omni) and xAI: Grok 4?

GPT-4o (Omni) is developed by OpenAI while xAI: Grok 4 is developed by xAI. GPT-4o (Omni) has a 128K token context window vs xAI: Grok 4's 256K. These results are based on blind head-to-head voting across 53 challenges.

Which is better, GPT-4o (Omni) or xAI: Grok 4?

Based on 2 community votes on Rival, GPT-4o (Omni) and xAI: Grok 4 are closely matched with similar win rates. The better choice depends on your specific use case. Compare their real outputs side-by-side across 53 challenges to decide.

How much does GPT-4o (Omni) cost compared to xAI: Grok 4?

GPT-4o (Omni) costs $2.5/M input tokens and xAI: Grok 4 costs $3/M input tokens. GPT-4o (Omni) is $0.50/M cheaper per input. The more expensive model wins 50% of duels, so the premium may be justified by quality.

How are GPT-4o (Omni) vs xAI: Grok 4 votes collected on Rival?

Rival presents both models' outputs side-by-side in blind duels. Voters see the responses but don't know which model produced each one, eliminating brand bias. 2 votes have been collected for this pair across 53 challenges. All vote data is part of Rival's open dataset.

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

Updated Jul 2025

Our Verdict

xAI: Grok 4Winner

GPT-4o (Omni)Runner-up

Votes are tied. xAI: Grok 4 is newer and likely incorporates more recent improvements.

Too close to call

API pricing

Cost per 1M tokens

GPT-4o (Omni)

Input

$2.50

1.2× cheaper

Output

$10.00

1.5× cheaper

xAI: Grok 4

Input

$3.00

Output

$15.00

GPT-4o (Omni) is cheaper on both — 1.2× input, 1.5× output

Writing DNA

Style Comparison

Similarity

47%

GPT-4o (Omni) uses 6.0x more transitions

GPT-4o (Omni)

xAI: Grok 4

54%Vocabulary53%

18wSentence Length18w

0.72Hedging0.67

7.3Bold2.7

5.6Lists2.7

0.03Emoji0.07

1.40Headings0.86

0.26Transitions0.04

Based on 24 + 21 text responses

Research

What we learned reading every model

GPT-4o (Omni) and xAI: Grok 4 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

xAI: Grok 4 vs GPT-5Cross-provider

Updated Jul 2025

Our Verdict

xAI: Grok 4Winner

GPT-4o (Omni)Runner-up

Votes are tied. xAI: Grok 4 is newer and likely incorporates more recent improvements.

Too close to call

API pricing

Cost per 1M tokens

GPT-4o (Omni)

Input

$2.50

1.2× cheaper

Output

$10.00

1.5× cheaper

xAI: Grok 4

Input

$3.00

Output

$15.00

GPT-4o (Omni) is cheaper on both — 1.2× input, 1.5× output

Writing DNA

Style Comparison

Similarity

47%

GPT-4o (Omni) uses 6.0x more transitions

GPT-4o (Omni)

xAI: Grok 4

54%Vocabulary53%

18wSentence Length18w

0.72Hedging0.67

7.3Bold2.7

5.6Lists2.7

0.03Emoji0.07

1.40Headings0.86

0.26Transitions0.04

Based on 24 + 21 text responses

Research

What we learned reading every model

GPT-4o (Omni) and xAI: Grok 4 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

xAI: Grok 4 vs GPT-5Cross-provider