GPT-5 Pro vs GPT-5.5
Compare GPT-5 Pro and GPT-5.5, both from OpenAI, context windows of 400K vs 1.1M, tested across 41 shared challenges.
Our Verdict
GPT-5.5
GPT-5 ProRunner-up
No community votes yet. On paper, GPT-5.5 has the edge — newer, bigger context window.
GPT-5.5 is 4.0x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
GPT-5 Pro
Input
$15.00
Output
$120.00
GPT-5.5
Input
$5.00
3.0× cheaper
Output
$30.00
4.0× cheaper
GPT-5.5 is cheaper on both — 3.0× input, 4.0× output
Writing DNA
Style Comparison
Similarity
50%
GPT-5.5 uses 285.6x more bold
GPT-5 Pro
GPT-5.5
65%Vocabulary58%
15wSentence Length18w
0.32Hedging0.74
0.0Bold2.9
2.9Lists5.1
0.00Emoji0.00
0.00Headings1.68
0.01Transitions0.03
Based on 11 + 26 text responses
Research
What we learned reading every model
FAQ
