GPT-5.1-Codex vs GPT-5.4
Compare GPT-5.1-Codex and GPT-5.4, both from OpenAI, context windows of 400K vs 1.1M, tested across 52 shared challenges.
Our Verdict
GPT-5.4
GPT-5.1-CodexRunner-up
No community votes yet. On paper, GPT-5.4 has the edge — newer, bigger context window.
Too close to call
API pricing
Cost per 1M tokens
GPT-5.1-Codex
Input
$1.25
2.0× cheaper
Output
$10.00
1.5× cheaper
GPT-5.4
Input
$2.50
Output
$15.00
GPT-5.1-Codex is cheaper on both — 2.0× input, 1.5× output
Writing DNA
Style Comparison
Similarity
43%
GPT-5.1-Codex uses 20.9x more transitions
GPT-5.1-Codex
GPT-5.4
70%Vocabulary54%
17wSentence Length28w
0.39Hedging0.69
3.4Bold4.1
3.5Lists8.1
0.00Emoji0.00
0.50Headings1.84
0.38Transitions0.02
Based on 14 + 22 text responses
Research
What we learned reading every model
FAQ
