Claude Sonnet 4.5 vs Z.AI: GLM 4.5 Air
Compare Claude Sonnet 4.5 by Anthropic against Z.AI: GLM 4.5 Air by Zhipu AI, context windows of 200K vs 128K, tested across 42 shared challenges.
Our Verdict
Claude Sonnet 4.5
Z.AI: GLM 4.5 AirRunner-up
No community votes yet. On paper, Claude Sonnet 4.5 has the edge — newer, bigger context window.
Z.AI: GLM 4.5 Air is 14x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Claude Sonnet 4.5
Input
$3.00
Output
$15.00
Z.AI: GLM 4.5 Air
Input
$0.20
15× cheaper
Output
$1.10
14× cheaper
Z.AI: GLM 4.5 Air is cheaper on both — 15× input, 14× output
Writing DNA
Style Comparison
Similarity
46%
Claude Sonnet 4.5 uses 5.8x more sentence length
Claude Sonnet 4.5
Z.AI: GLM 4.5 Air
64%Vocabulary48%
94wSentence Length16w
0.48Hedging0.40
4.9Bold5.4
8.0Lists4.8
0.45Emoji0.10
1.91Headings0.75
0.07Transitions0.12
Based on 20 + 15 text responses
Research
What we learned reading every model
FAQ
