GPT-5.1-Codex-Mini vs GPT-5.5
Compare GPT-5.1-Codex-Mini and GPT-5.5, both from OpenAI, context windows of 400K vs 1.1M, tested across 54 shared challenges.
Our Verdict
GPT-5.5
GPT-5.1-Codex-MiniRunner-up
No community votes yet. On paper, GPT-5.5 has the edge — newer, bigger context window.
GPT-5.1-Codex-Mini is 5.0x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
GPT-5.1-Codex-Mini
Input
$1.50
3.3× cheaper
Output
$6.00
5.0× cheaper
GPT-5.5
Input
$5.00
Output
$30.00
GPT-5.1-Codex-Mini is cheaper on both — 3.3× input, 5.0× output
Writing DNA
Style Comparison
Similarity
48%
GPT-5.5 uses 21.7x more headings
GPT-5.1-Codex-Mini
GPT-5.5
65%Vocabulary58%
20wSentence Length18w
0.56Hedging0.74
3.3Bold2.9
3.4Lists5.1
0.00Emoji0.00
0.08Headings1.68
0.05Transitions0.03
Based on 13 + 26 text responses
Research
What we learned reading every model
FAQ
