GPT-5.3-Codex vs OpenAI o4-mini
Compare GPT-5.3-Codex and OpenAI o4-mini, both from OpenAI, tested across 53 shared challenges.
Our Verdict
GPT-5.3-Codex
OpenAI o4-miniRunner-up
No community votes yet. On paper, GPT-5.3-Codex has the edge — bigger model tier, newer, bigger context window.
OpenAI o4-mini is 3.2x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
GPT-5.3-Codex
Input
$1.75
Output
$14.00
OpenAI o4-mini
Input
$1.10
1.6× cheaper
Output
$4.40
3.2× cheaper
OpenAI o4-mini is cheaper on both — 1.6× input, 3.2× output
Writing DNA
Style Comparison
Similarity
42%
GPT-5.3-Codex uses 654.6x more bold
GPT-5.3-Codex
OpenAI o4-mini
65%Vocabulary73%
23wSentence Length15w
0.51Hedging0.18
6.5Bold0.0
6.2Lists2.1
0.16Emoji0.00
1.90Headings0.00
0.03Transitions0.02
Based on 23 + 10 text responses
Research
What we learned reading every model
FAQ
