GPT-5 vs GPT-5.3-Codex
Compare GPT-5 and GPT-5.3-Codex, both from OpenAI, context windows of 400K vs 400K, tested across 51 shared challenges.
Our Verdict
GPT-5
GPT-5.3-Codex
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
API pricing
Cost per 1M tokens
GPT-5
Input
$1.25
1.4× cheaper
Output
$10.00
1.4× cheaper
GPT-5.3-Codex
Input
$1.75
Output
$14.00
GPT-5 is cheaper on both — 1.4× input, 1.4× output
Writing DNA
Style Comparison
Similarity
53%
GPT-5.3-Codex uses 15.8x more emoji
GPT-5
GPT-5.3-Codex
65%Vocabulary65%
13wSentence Length23w
0.20Hedging0.51
0.2Bold6.5
4.6Lists6.2
0.00Emoji0.16
0.16Headings1.90
0.03Transitions0.03
Based on 16 + 23 text responses
Research
What we learned reading every model
FAQ
