What is the difference between Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max?

Gemini 2.5 Pro (I/O Edition) is developed by Google AI while GPT-5.1 Codex Max is developed by OpenAI. You can compare their actual outputs across 41 challenges on Rival to see how they differ in practice.

Which is better, Gemini 2.5 Pro (I/O Edition) or GPT-5.1 Codex Max?

It depends on your use case. Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 41 challenges so you can judge which fits your needs best.

How can I compare Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max on Rival?

This page shows a side-by-side comparison of Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max 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 Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max?

Gemini 2.5 Pro (I/O Edition) is developed by Google AI while GPT-5.1 Codex Max is developed by OpenAI. You can compare their actual outputs across 41 challenges on Rival to see how they differ in practice.

Which is better, Gemini 2.5 Pro (I/O Edition) or GPT-5.1 Codex Max?

It depends on your use case. Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 41 challenges so you can judge which fits your needs best.

How can I compare Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max on Rival?

This page shows a side-by-side comparison of Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max 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.

Gemini 2.5 Pro (I/O Edition) vs GPT-5.1 Codex Max: Which Is Better?

Updated Dec 2025

Our Verdict

Gemini 2.5 Pro (I/O Edition)

GPT-5.1 Codex Max

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

Gemini 2.5 Pro (I/O Edition)

Input

$1.25

Output

$10.00

GPT-5.1 Codex Max

Input

—

Output

—

Writing DNA

Style Comparison

Similarity

59%

Gemini 2.5 Pro (I/O Edition) uses 5.1x more headings

Gemini 2.5 Pro (I/O Edition)

GPT-5.1 Codex Max

58%Vocabulary60%

16wSentence Length16w

0.38Hedging0.36

5.8Bold2.3

5.0Lists4.2

0.00Emoji0.00

0.63Headings0.12

0.01Transitions0.03

Based on 16 + 13 text responses

Research

What we learned reading every model

Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max 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

Gemini 2.5 Pro (I/O Edition) vs MiniMax M3New provider

Gemini 2.5 Pro (I/O Edition) vs Grok 3New provider

Gemini 2.5 Pro (I/O Edition) vs Llama 4 MaverickNew provider

Updated Dec 2025

Our Verdict

Gemini 2.5 Pro (I/O Edition)

GPT-5.1 Codex Max

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

Gemini 2.5 Pro (I/O Edition)

Input

$1.25

Output

$10.00

GPT-5.1 Codex Max

Input

—

Output

—

Writing DNA

Style Comparison

Similarity

59%

Gemini 2.5 Pro (I/O Edition) uses 5.1x more headings

Gemini 2.5 Pro (I/O Edition)

GPT-5.1 Codex Max

58%Vocabulary60%

16wSentence Length16w

0.38Hedging0.36

5.8Bold2.3

5.0Lists4.2

0.00Emoji0.00

0.63Headings0.12

0.01Transitions0.03

Based on 16 + 13 text responses

Research

What we learned reading every model

Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max 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

Gemini 2.5 Pro (I/O Edition) vs MiniMax M3New provider

Gemini 2.5 Pro (I/O Edition) vs Grok 3New provider

Gemini 2.5 Pro (I/O Edition) vs Llama 4 MaverickNew provider