DeepSeek V4 Flash vs GPT-5.5
Compare DeepSeek V4 Flash by DeepSeek against GPT-5.5 by OpenAI, context windows of 1.0M vs 1.1M, tested across 54 shared challenges.
Our Verdict
GPT-5.5
DeepSeek V4 FlashRunner-up
No community votes yet. On paper, GPT-5.5 has the edge — bigger model tier.
DeepSeek V4 Flash is 107x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
DeepSeek V4 Flash
Input
$0.14
36× cheaper
Output
$0.28
107× cheaper
GPT-5.5
Input
$5.00
Output
$30.00
DeepSeek V4 Flash is cheaper on both — 36× input, 107× output
Writing DNA
Style Comparison
Similarity
43%
DeepSeek V4 Flash uses 5.4x more transitions
DeepSeek V4 Flash
GPT-5.5
54%Vocabulary58%
17wSentence Length18w
0.52Hedging0.74
3.6Bold2.9
2.6Lists5.1
0.00Emoji0.00
0.41Headings1.68
0.19Transitions0.03
Based on 27 + 26 text responses
Research
What we learned reading every model
FAQ
