Claude Opus 4 vs GPT-5.1 Codex Max
Compare Claude Opus 4 by Anthropic against GPT-5.1 Codex Max by OpenAI, tested across 52 shared challenges. Updated June 2026.
Which is better, Claude Opus 4 or GPT-5.1 Codex Max?
Claude Opus 4 and GPT-5.1 Codex Max are both competitive models. Compare their real outputs side by side below.
Key Differences Between Claude Opus 4 and GPT-5.1 Codex Max
Claude Opus 4 is made by anthropic while GPT-5.1 Codex Max is from openai.
API pricing
Per 1M tokens
Claude Opus 4
Input
$15.00
Output
$75.00
GPT-5.1 Codex Max
Input
—
Output
—
Our Verdict
Claude Opus 4
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
38%
Claude Opus 4 uses 11.2x more emoji
Claude Opus 4
GPT-5.1 Codex Max
64%Vocabulary60%
62wSentence Length16w
0.52Hedging0.36
4.4Bold2.3
9.1Lists4.2
0.11Emoji0.00
1.87Headings0.12
0.27Transitions0.03
Based on 16 + 13 text responses
FAQ
