Z.AI: GLM 4.5 Air vs GPT OSS 20B
Compare Z.AI: GLM 4.5 Air by Zhipu AI against GPT OSS 20B by OpenAI, context windows of 128K vs 131K, tested across 53 shared challenges.
Our Verdict
Z.AI: GLM 4.5 Air
GPT OSS 20B
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
GPT OSS 20B is 11x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Z.AI: GLM 4.5 Air
Input
$0.20
Output
$1.10
GPT OSS 20B
Input
$0.02
10× cheaper
Output
$0.10
11× cheaper
GPT OSS 20B is cheaper on both — 10× input, 11× output
Writing DNA
Style Comparison
Similarity
49%
GPT OSS 20B uses 2.6x more transitions
Z.AI: GLM 4.5 Air
GPT OSS 20B
48%Vocabulary54%
16wSentence Length17w
0.40Hedging0.26
5.4Bold5.9
4.8Lists3.3
0.10Emoji0.10
0.75Headings0.75
0.12Transitions0.32
Based on 15 + 21 text responses
Research
What we learned reading every model
FAQ
