Gemini 2.5 Pro (I/O Edition) vs GPT-5.1 Codex Max
Compare Gemini 2.5 Pro (I/O Edition) by Google AI against GPT-5.1 Codex Max by OpenAI, tested across 41 shared challenges. Updated June 2026.
Which is better, Gemini 2.5 Pro (I/O Edition) or GPT-5.1 Codex Max?
Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max are both competitive models. Compare their real outputs side by side below.
Key Differences Between Gemini 2.5 Pro (I/O Edition) and GPT-5.1 Codex Max
Gemini 2.5 Pro (I/O Edition) is made by google while GPT-5.1 Codex Max is from openai.
API pricing
Per 1M tokens
Gemini 2.5 Pro (I/O Edition)
Input
$1.25
Output
$10.00
GPT-5.1 Codex Max
Input
—
Output
—
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
Writing DNA
Style Comparison
Similarity
58%
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
FAQ
