GPT-5.4 Pro vs GPT-5.5
Compare GPT-5.4 Pro and GPT-5.5, both from OpenAI, context windows of 1.1M vs 1.1M, tested across 18 shared challenges.
Our Verdict
GPT-5.4 Pro
GPT-5.5
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
GPT-5.5 is 6.0x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
GPT-5.4 Pro
Input
$30.00
Output
$180.00
GPT-5.5
Input
$5.00
6.0× cheaper
Output
$30.00
6.0× cheaper
GPT-5.5 is cheaper on both — 6.0× input, 6.0× output
Writing DNA
Style Comparison
Similarity
73%
GPT-5.5 uses 3.4x more transitions
GPT-5.4 Pro
GPT-5.5
50%Vocabulary58%
35wSentence Length18w
0.70Hedging0.74
7.5Bold2.9
8.3Lists5.1
0.00Emoji0.00
2.52Headings1.68
0.01Transitions0.03
Based on 12 + 26 text responses
Research
What we learned reading every model
FAQ
