Claude Opus 4 vs GPT-5.1-Codex-Mini
Compare Claude Opus 4 by Anthropic against GPT-5.1-Codex-Mini by OpenAI, context windows of 200K vs 400K, tested across 53 shared challenges.
Our Verdict
GPT-5.1-Codex-Mini
Claude Opus 4Runner-up
No community votes yet. On paper, GPT-5.1-Codex-Mini has the edge — newer, bigger context window.
GPT-5.1-Codex-Mini is 13x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Claude Opus 4
Input
$15.00
Output
$75.00
GPT-5.1-Codex-Mini
Input
$1.50
10× cheaper
Output
$6.00
13× cheaper
GPT-5.1-Codex-Mini is cheaper on both — 10× input, 13× output
Writing DNA
Style Comparison
Similarity
34%
Claude Opus 4 uses 11.2x more emoji
Claude Opus 4
GPT-5.1-Codex-Mini
64%Vocabulary65%
62wSentence Length20w
0.52Hedging0.56
4.4Bold3.3
9.1Lists3.4
0.11Emoji0.00
1.87Headings0.08
0.27Transitions0.05
Based on 16 + 13 text responses
Research
What we learned reading every model
FAQ
