Claude Opus 4.1 vs Z.AI: GLM 4.5 Air
Compare Claude Opus 4.1 by Anthropic against Z.AI: GLM 4.5 Air by Zhipu AI, context windows of 200K vs 128K, tested across 53 shared challenges.
Our Verdict
Claude Opus 4.1
Z.AI: GLM 4.5 AirRunner-up
No community votes yet. On paper, Claude Opus 4.1 has the edge — bigger model tier, bigger context window.
Z.AI: GLM 4.5 Air is 68x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Claude Opus 4.1
Input
$15.00
Output
$75.00
Z.AI: GLM 4.5 Air
Input
$0.20
75× cheaper
Output
$1.10
68× cheaper
Z.AI: GLM 4.5 Air is cheaper on both — 75× input, 68× output
Writing DNA
Style Comparison
Similarity
49%
Claude Opus 4.1 uses 5.4x more sentence length
Claude Opus 4.1
Z.AI: GLM 4.5 Air
61%Vocabulary48%
87wSentence Length16w
0.54Hedging0.40
5.1Bold5.4
6.7Lists4.8
0.38Emoji0.10
1.68Headings0.75
0.13Transitions0.12
Based on 17 + 15 text responses
Research
What we learned reading every model
FAQ
