A Browser Tool Scores How Much Your Setup Looks Like a Chinese User to Claude Code

Someone built a webpage to self-test whether Claude Code would flag you as a Chinese user.

Author: 逛逛GitHub Tags: GitHub

Someone open-sourced a small tool on GitHub called FuckClaude.

It lets you run a one-click self-test in the browser to see how much your environment resembles a Chinese user in the eyes of Claude Code.

The author turned six browser characteristics into a scoring model, with the weights adding up to exactly 100 points.

• System timezone: 30 points, e.g., Asia/Shanghai — this is a signal Claude actually uses
• Browser language: 24 points, e.g., zh-CN or zh-Hans gets full marks
• Installed Chinese fonts: 20 points, using canvas width detection for fonts like Microsoft YaHei and PingFang SC
• Intl locale settings: 10 points
• Timezone offset: 8 points (UTC+8)
• Emoji rendering style: 8 points, inferred from the User-Agent to determine the system vendor

Each item gets a similarity score from 0 to 1, multiplied by its weight, then summed up.

In the end, you get a verdict of Low, Medium, or High.

Open-source repo: https://github.com/LinXiaoTao/FuckClaude