What is the difference between GPT-5 Codex and xAI: Grok 4?

GPT-5 Codex is developed by OpenAI while xAI: Grok 4 is developed by xAI. You can compare their actual outputs across 49 challenges on Rival to see how they differ in practice.

Which is better, GPT-5 Codex or xAI: Grok 4?

It depends on your use case. GPT-5 Codex and xAI: Grok 4 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 49 challenges so you can judge which fits your needs best.

How can I compare GPT-5 Codex and xAI: Grok 4 on Rival?

This page shows a side-by-side comparison of GPT-5 Codex and xAI: Grok 4 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-5 Codex and xAI: Grok 4?

GPT-5 Codex is developed by OpenAI while xAI: Grok 4 is developed by xAI. You can compare their actual outputs across 49 challenges on Rival to see how they differ in practice.

Which is better, GPT-5 Codex or xAI: Grok 4?

It depends on your use case. GPT-5 Codex and xAI: Grok 4 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 49 challenges so you can judge which fits your needs best.

How can I compare GPT-5 Codex and xAI: Grok 4 on Rival?

This page shows a side-by-side comparison of GPT-5 Codex and xAI: Grok 4 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-5 Codex vs xAI: Grok 4: Which Is Better?

Updated Sep 2025

Our Verdict

GPT-5 Codex

xAI: Grok 4Runner-up

No community votes yet. On paper, GPT-5 Codex has the edge — bigger model tier, newer.

Too close to call

API pricing

Cost per 1M tokens

GPT-5 Codex

Input

—

Output

—

xAI: Grok 4

Input

$3.00

Output

$15.00

Writing DNA

Style Comparison

Similarity

44%

GPT-5 Codex uses 2.1x more emoji

GPT-5 Codex

xAI: Grok 4

64%Vocabulary53%

17wSentence Length18w

0.38Hedging0.67

2.3Bold2.7

3.5Lists2.7

0.15Emoji0.07

0.49Headings0.86

0.05Transitions0.04

Based on 13 + 21 text responses

Research

What we learned reading every model

GPT-5 Codex 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-5 Codex vs MiniMax M3New provider

GPT-5 Codex vs Llama 4 MaverickNew provider

GPT-5 Codex vs Gemini 2.5 Pro (I/O Edition)New provider

Updated Sep 2025

Our Verdict

GPT-5 Codex

xAI: Grok 4Runner-up

No community votes yet. On paper, GPT-5 Codex has the edge — bigger model tier, newer.

Too close to call

API pricing

Cost per 1M tokens

GPT-5 Codex

Input

—

Output

—

xAI: Grok 4

Input

$3.00

Output

$15.00

Writing DNA

Style Comparison

Similarity

44%

GPT-5 Codex uses 2.1x more emoji

GPT-5 Codex

xAI: Grok 4

64%Vocabulary53%

17wSentence Length18w

0.38Hedging0.67

2.3Bold2.7

3.5Lists2.7

0.15Emoji0.07

0.49Headings0.86

0.05Transitions0.04

Based on 13 + 21 text responses

Research

What we learned reading every model

GPT-5 Codex 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-5 Codex vs MiniMax M3New provider

GPT-5 Codex vs Llama 4 MaverickNew provider

GPT-5 Codex vs Gemini 2.5 Pro (I/O Edition)New provider