Claude Opus 4.1 vs Google: Gemini 2.5 Flash Preview 09-2025
Compare Claude Opus 4.1 by Anthropic against Google: Gemini 2.5 Flash Preview 09-2025 by Google AI, context windows of 200K vs 1.0M, tested across 50 shared challenges.
Our Verdict
Google: Gemini 2.5 Flash Preview 09-2025
Claude Opus 4.1Runner-up
No community votes yet. On paper, Google: Gemini 2.5 Flash Preview 09-2025 has the edge — newer, bigger context window.
Google: Gemini 2.5 Flash Preview 09-2025 is 30x 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
Google: Gemini 2.5 Flash Preview 09-2025
Input
$0.30
50× cheaper
Output
$2.50
30× cheaper
Google: Gemini 2.5 Flash Preview 09-2025 is cheaper on both — 50× input, 30× output
Writing DNA
Style Comparison
Similarity
44%
Claude Opus 4.1 uses 4.7x more sentence length
Claude Opus 4.1
Google: Gemini 2.5 Flash Preview 09-2025
61%Vocabulary53%
87wSentence Length19w
0.54Hedging0.30
5.1Bold5.8
6.7Lists3.1
0.38Emoji0.14
1.68Headings0.93
0.13Transitions0.22
Based on 17 + 22 text responses
Research
What we learned reading every model
FAQ
