Google: Gemini 2.5 Flash Preview 09-2025 vs Z.ai: GLM 5.1
Compare Google: Gemini 2.5 Flash Preview 09-2025 by Google AI against Z.ai: GLM 5.1 by Z-ai, context windows of 1.0M vs 203K, tested across 49 shared challenges.
Our Verdict
Google: Gemini 2.5 Flash Preview 09-2025
Z.ai: GLM 5.1Runner-up
No community votes yet. On paper, Google: Gemini 2.5 Flash Preview 09-2025 has the edge — bigger model tier, bigger context window, major provider backing.
Too close to call
API pricing
Cost per 1M tokens
Google: Gemini 2.5 Flash Preview 09-2025
Input
$0.30
4.7× cheaper
Output
$2.50
1.8× cheaper
Z.ai: GLM 5.1
Input
$1.40
Output
$4.40
Google: Gemini 2.5 Flash Preview 09-2025 is cheaper on both — 4.7× input, 1.8× output
Writing DNA
Style Comparison
Similarity
59%
Google: Gemini 2.5 Flash Preview 09-2025 uses 13.5x more emoji
Google: Gemini 2.5 Flash Preview 09-2025
Z.ai: GLM 5.1
53%Vocabulary54%
19wSentence Length18w
0.30Hedging0.31
5.8Bold3.6
3.1Lists2.6
0.14Emoji0.00
0.93Headings0.43
0.22Transitions0.11
Based on 22 + 27 text responses
Research
What we learned reading every model
FAQ
