GPT-5.1 vs GPT OSS 20B
Compare GPT-5.1 and GPT OSS 20B, both from OpenAI, context windows of 400K vs 131K, tested across 52 shared challenges.
Our Verdict
GPT-5.1
GPT OSS 20BRunner-up
No community votes yet. On paper, GPT-5.1 has the edge — bigger model tier, newer, bigger context window.
GPT OSS 20B is 100x cheaper per token — worth considering if cost matters.
Slight edge
API pricing
Cost per 1M tokens
GPT-5.1
Input
$1.25
Output
$10.00
GPT OSS 20B
Input
$0.02
63× cheaper
Output
$0.10
100× cheaper
GPT OSS 20B is cheaper on both — 63× input, 100× output
Writing DNA
Style Comparison
Similarity
35%
GPT OSS 20B uses 10.2x more emoji
GPT-5.1
GPT OSS 20B
62%Vocabulary54%
19wSentence Length17w
0.29Hedging0.26
3.5Bold5.9
7.2Lists3.3
0.00Emoji0.10
0.61Headings0.75
0.03Transitions0.32
Based on 14 + 21 text responses
Research
What we learned reading every model
FAQ
Common questions
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