GPT-5.3 Chat vs GPT-5.4 Pro
Compare GPT-5.3 Chat and GPT-5.4 Pro, both from OpenAI, context windows of 128K vs 1.1M, tested across 18 shared challenges.
Our Verdict
GPT-5.4 Pro
GPT-5.3 ChatRunner-up
No community votes yet. On paper, GPT-5.4 Pro has the edge — bigger model tier, bigger context window.
GPT-5.3 Chat is 13x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
GPT-5.3 Chat
Input
$1.75
17× cheaper
Output
$14.00
13× cheaper
GPT-5.4 Pro
Input
$30.00
Output
$180.00
GPT-5.3 Chat is cheaper on both — 17× input, 13× output
Writing DNA
Style Comparison
Similarity
50%
GPT-5.4 Pro uses 251.6x more headings
GPT-5.3 Chat
GPT-5.4 Pro
59%Vocabulary50%
26wSentence Length35w
0.84Hedging0.70
1.7Bold7.5
6.6Lists8.3
0.00Emoji0.00
0.00Headings2.52
0.25Transitions0.01
Based on 23 + 12 text responses
Research
What we learned reading every model
FAQ
