What is the difference between GPT-5.1 Codex Max and Grok 4.20 Beta?

GPT-5.1 Codex Max is developed by OpenAI while Grok 4.20 Beta is developed by xAI. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 Codex Max or Grok 4.20 Beta?

It depends on your use case. GPT-5.1 Codex Max and Grok 4.20 Beta each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.

How can I compare GPT-5.1 Codex Max and Grok 4.20 Beta on Rival?

This page shows a side-by-side comparison of GPT-5.1 Codex Max and Grok 4.20 Beta 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-5.1 Codex Max and Grok 4.20 Beta?

GPT-5.1 Codex Max is developed by OpenAI while Grok 4.20 Beta is developed by xAI. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 Codex Max or Grok 4.20 Beta?

It depends on your use case. GPT-5.1 Codex Max and Grok 4.20 Beta each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.

How can I compare GPT-5.1 Codex Max and Grok 4.20 Beta on Rival?

This page shows a side-by-side comparison of GPT-5.1 Codex Max and Grok 4.20 Beta 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-5.1 Codex Max vs Grok 4.20 Beta: Which Is Better?

Updated Mar 2026

Our Verdict

GPT-5.1 Codex Max

Grok 4.20 Beta

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-5.1 Codex Max

Input

—

Output

—

Grok 4.20 Beta

Input

$2.00

Output

$6.00

Writing DNA

Style Comparison

Similarity

52%

Grok 4.20 Beta uses 5.3x more transitions

GPT-5.1 Codex Max

Grok 4.20 Beta

60%Vocabulary57%

16wSentence Length20w

0.36Hedging0.35

2.3Bold4.2

4.2Lists3.7

0.00Emoji0.00

0.12Headings0.62

0.03Transitions0.14

Based on 13 + 23 text responses

Research

What we learned reading every model

GPT-5.1 Codex Max and Grok 4.20 Beta 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-5.1 Codex Max vs MiniMax M3New provider

GPT-5.1 Codex Max vs Claude Opus 4New provider

GPT-5.1 Codex Max vs Gemini 2.5 Pro Preview 06-05New provider

Updated Mar 2026

Our Verdict

GPT-5.1 Codex Max

Grok 4.20 Beta

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-5.1 Codex Max

Input

—

Output

—

Grok 4.20 Beta

Input

$2.00

Output

$6.00

Writing DNA

Style Comparison

Similarity

52%

Grok 4.20 Beta uses 5.3x more transitions

GPT-5.1 Codex Max

Grok 4.20 Beta

60%Vocabulary57%

16wSentence Length20w

0.36Hedging0.35

2.3Bold4.2

4.2Lists3.7

0.00Emoji0.00

0.12Headings0.62

0.03Transitions0.14

Based on 13 + 23 text responses

Research

What we learned reading every model

GPT-5.1 Codex Max and Grok 4.20 Beta 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-5.1 Codex Max vs MiniMax M3New provider

GPT-5.1 Codex Max vs Claude Opus 4New provider

GPT-5.1 Codex Max vs Gemini 2.5 Pro Preview 06-05New provider