English | 中文
A lightweight, SEO-friendly, bilingual (EN / 中文) single-page tool that scans your browser environment and tells you whether Claude Code would flag you as a China user. One click runs an animated scan of each signal, the gauge climbs as risk adds up, and you get a verdict plus the list of matched signals. Everything runs 100% locally — no network requests, no data upload.
Built with Claude Fable 5.
When Claude Code is pointed at a non-official endpoint via ANTHROPIC_BASE_URL, it
was reported to read the system timezone and the proxy hostname, then encode
the result steganographically into the Today's date is … line of the system prompt
(date separator - → / on a China timezone; the apostrophe swapped among four
near-identical Unicode variants to encode domain-list / AI-lab-keyword hits).
A web page can only read browser-visible signals. Crucially, Intl reads the same
OS timezone Claude Code does, so timezone is the one signal that maps directly onto
Claude's real check. The other signals are general "Chinese environment" fingerprints.
| 🏆 Sponsors 🏆 | Introduction |
|---|---|
 |
Ergou API Thanks to Ergou API for sponsoring this project! Ergou API is the rock-solid AI API gateway: ultra-low multipliers (0.1x–0.2x) across the board, with 100% genuine, unfiltered endpoints for top-tier LLMs including Claude, GPT and Gemini. Powered by premium IPLC routes and dual residential ISP redundancy for battle-tested stability and ultra-low latency. Built for developers and studios — sign up and start building today. |
 |
Roxy Browser | Multi-account farming & anti-ban (10% off promo code) Thanks to Roxy Browser for sponsoring this project! Built to bypass AI-platform risk-control checks: fully masks Canvas, WebGL and other low-level fingerprints, gives every account absolute physical isolation, and keeps batch account farming stable and ban-free. |
 |
AgentEarth Thanks to AgentEarth for sponsoring this project! Your agent needs tools that get things done right: AgentEarth puts 600+ plug-and-play external API tools — AI generation, web search, scraping, maps, weather, finance data and more — behind a single MCP endpoint. Get started today. |
| Signal | Weight | How it's detected |
|---|---|---|
| System timezone | 30 | Intl.DateTimeFormat().resolvedOptions().timeZone vs. Asia/Shanghai, Asia/Urumqi, … (used by Claude) |
| Browser language | 24 | navigator.language(s); zh-CN / zh-Hans scores highest |
| Installed Chinese fonts | 20 | Canvas width-probing for SC/TC fonts (Microsoft YaHei, PingFang SC, …) |
| Intl locale | 10 | Intl resolved locale (date/number formatting) |
| Timezone offset | 8 | getTimezoneOffset() === -480 (UTC+8) |
| Emoji rendering style | 8 | OS-vendor guess from platform/UA; weakly correlated |
Each signal returns a 0–1 "China-like" score, multiplied by its weight; the six
weights sum to 100, so the total score is the sum of contributions. Bands: Low
0–30, Medium 31–60, High 61–100. A signal counts as a "hit" when its score
≥ 0.25.
- Astro
7.x, static output (output: 'static') - Built-in i18n: English at
/, Chinese at/zh/, plus@astrojs/sitemap - No UI framework; the scan/scoring logic is a single bundled TypeScript module
- Package manager: pnpm
src/
├── config/signals.ts # signal definitions, weights, detectors, icons
├── config/sponsors.ts # sponsor list (logo, link, EN/ZH taglines)
├── config/cn-models.ts # domestic-model picks (DeepSeek / GLM / Kimi name-only links)
├── i18n/ui.ts # EN/ZH copy dictionary + translator
├── scripts/detect.ts # animated scan + scoring + verdict (client)
├── scripts/track.ts # GA click tracking for outbound promo links
├── layouts/BaseLayout.astro # <head> SEO + GA + global styles
├── components/ # Detector, Sponsors, CnModels, ScoreRing, Mascot (animated Claude-CEO), LangToggle, Footer
└── pages/ # index.astro (en) + zh/index.astro
public/mascot/ # cartoon CEO state images (doze / search / low / medium / high)
public/sponsors/ # sponsor logos
scripts/
└── gen-assets.mjs # regenerates favicon / PWA icons / og.png (node scripts/gen-assets.mjs)
pnpm install
pnpm dev # http://localhost:4321
pnpm build # -> dist/
pnpm previewAny static host (Cloudflare Pages, Vercel, Netlify, GitHub Pages). Before deploying,
set your real origin in astro.config.mjs (site) and
public/robots.txt so canonical URLs, hreflang links and the
sitemap point to the correct domain.
For reference only, based on public reverse-engineering reports of Claude Code's former proxy-fingerprinting behaviour. Not an official statement or advice.
English | 中文
一个轻量、SEO 友好、中英双语的单页工具:扫描你的浏览器环境,判断你是否会被 Claude Code 标记为中国用户。点击后会有逐项检测的扫描动效,分数环随风险累加而增长, 最后给出结论与命中的信号列表。所有检测都在本地浏览器完成——不发起任何网络请求, 不上传任何数据。
本网站使用 Claude Fable 5 开发。
当 Claude Code 通过 ANTHROPIC_BASE_URL 指向非官方中转时,据公开逆向分析它会读取
系统时区与中转 hostname,再把结果用隐写术编码进 system prompt 的
Today's date is … 这一行(命中中国时区时日期分隔符 - 变 /;撇号在 4 种视觉几乎
相同的 Unicode 变体间切换,编码是否命中域名清单 / AI 实验室关键词)。
网页只能读取浏览器可见信号。关键在于:Intl 读到的时区与 Claude Code 读的是同一个
操作系统时区,因此时区是唯一能直接对应 Claude 真实判定的信号;其余信号属于更广义的
「中文环境指纹」。
| 🏆 赞助商 🏆 | 介绍 |
|---|---|
|
二狗 API 感谢 二狗 API 赞助本项目!接入二狗,稳如老狗。二狗 API 中转站全站 0.1x~0.2x 超低倍率,提供 Claude/GPT/Gemini 等多个国内外 100% 纯血大模型接口;顶级 IPLC 线路 + 住宅双 ISP 冗余,确保全国范围稳定低延迟访问。欢迎各位开发者、工作室注册使用。 |
|
Roxy 浏览器 | 养号&多账号防封号(优惠码 9 折) 感谢 Roxy 浏览器 赞助本项目!专为绕过 AI 平台风控检测而生!完美屏蔽 Canvas、WebGL 等底层指纹,实现多账号绝对物理隔离,批量养号稳定防封。 |
|
AgentEarth 感谢 AgentEarth 赞助本项目!你的智能体需要的是能把事情做对的工具:AgentEarth 把 600+ 即插即用的外部 API 工具——AI 生成、搜索、爬虫、地图、天气、金融数据等——汇聚在一个 MCP 接入点。欢迎立即接入。 |
| 信号 | 权重 | 检测方式 |
|---|---|---|
| 系统时区 | 30 | Intl.DateTimeFormat().resolvedOptions().timeZone 对比 Asia/Shanghai、Asia/Urumqi 等(Claude 实际使用) |
| 浏览器语言 | 24 | navigator.language(s);zh-CN / zh-Hans 得分最高 |
| 已安装中文字体 | 20 | canvas 宽度探测简/繁体中文字体(微软雅黑、PingFang SC 等) |
| Intl 区域设置 | 10 | Intl 解析出的 locale(日期 / 数字格式) |
| 时区偏移 | 8 | getTimezoneOffset() === -480(UTC+8) |
| Emoji 渲染风格 | 8 | 由平台 / UA 推断 OS 厂商,弱相关 |
每个信号输出 0–1 的「中国相似度」,乘以权重;六项权重合计为 100,所以总分即各项
贡献之和。分档:低 0–30、中 31–60、高 61–100。信号得分 ≥ 0.25 记为「命中」。
- Astro
7.x,静态输出(output: 'static') - 内置 i18n:英文在
/,中文在/zh/,并使用@astrojs/sitemap - 不依赖任何 UI 框架;扫描 / 打分逻辑是单个打包的 TypeScript 模块
- 包管理器:pnpm
src/
├── config/signals.ts # 信号定义、权重、检测函数、图标
├── config/sponsors.ts # 赞助商列表(logo、链接、中英文案)
├── config/cn-models.ts # 国产模型推荐(DeepSeek / GLM / Kimi 纯文字链接)
├── i18n/ui.ts # 中英文案字典 + 取值 helper
├── scripts/detect.ts # 扫描动效 + 打分 + 结论(客户端)
├── scripts/track.ts # 出站推广链接的 GA 点击埋点
├── layouts/BaseLayout.astro # <head> SEO + GA + 全局样式
├── components/ # Detector、Sponsors、CnModels、ScoreRing、Mascot(会动的 Claude CEO)、LangToggle、Footer
└── pages/ # index.astro(英)+ zh/index.astro(中)
public/mascot/ # 卡通 CEO 各状态图(打瞌睡 / 检测中 / 低 / 中 / 高风险)
public/sponsors/ # 赞助商 logo
scripts/
└── gen-assets.mjs # 重新生成 favicon / PWA 图标 / og.png(node scripts/gen-assets.mjs)
pnpm install
pnpm dev # http://localhost:4321
pnpm build # 产物在 dist/
pnpm preview支持任意静态托管(Cloudflare Pages、Vercel、Netlify、GitHub Pages)。部署前请把
astro.config.mjs 的 site 和 public/robots.txt
换成你的真实域名,以保证 canonical、hreflang 与 sitemap 指向正确。
本工具仅供参考,基于对 Claude Code 早期中转指纹行为的公开逆向分析,不构成任何官方结论 或建议。