GPT OSS 20B vs xAI: Grok 4.5
Compare GPT OSS 20B by OpenAI against xAI: Grok 4.5 by xAI, context windows of 131K vs 500K, tested across 53 shared challenges.
Our Verdict
xAI: Grok 4.5
GPT OSS 20BRunner-up
No community votes yet. On paper, xAI: Grok 4.5 has the edge — newer, bigger context window.
GPT OSS 20B is 60x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
GPT OSS 20B
Input
$0.02
100× cheaper
Output
$0.10
60× cheaper
xAI: Grok 4.5
Input
$2.00
Output
$6.00
GPT OSS 20B is cheaper on both — 100× input, 60× output
Writing DNA
Style Comparison
Similarity
48%
GPT OSS 20B uses 5.6x more transitions
GPT OSS 20B
xAI: Grok 4.5
54%Vocabulary61%
17wSentence Length16w
0.26Hedging0.23
5.9Bold2.5
3.3Lists2.4
0.10Emoji0.09
0.75Headings0.48
0.32Transitions0.06
Based on 21 + 27 text responses
Research
What we learned reading every model
FAQ
