CLAUDE ENVIRONMENT CHECK

Claude China-environment Risk Check

Inspect browser-visible timezone, language, fonts, browser and device characteristics to estimate how closely this environment resembles China-associated signals.

RESULT

Ready

Start the check to generate a 0–100 environment-similarity score.

This is not an official Claude decision and does not mean the account will necessarily be restricted.

0/ 100
Scoring runs in this browser; results are not uploaded

Primary reasons

Top 3 contributors
1
System timezoneWaiting
— / 24
2
Browser languagesWaiting
— / 18
3
Chinese system fontsWaiting
— / 14
ENVIRONMENT SIGNALS

Signal details

Weights are adapted from public reverse-engineering research and an open-source reference. A higher score only means greater similarity.

SignalObserved valueRisk contributionStatus

System timezone

Direct Claude signal

Reads the OS timezone exposed through Intl; this is the browser signal closest to reported Claude Code behavior.

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Weight 24

Browser languages

Checks navigator.languages for Simplified Chinese and regional preferences.

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Weight 18

Chinese system fonts

Uses Canvas width differences to check common Simplified and Traditional Chinese fonts.

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Weight 14

Chinese vendor fonts

Checks fonts commonly shipped by device vendors and Chinese software, such as MiSans and HarmonyOS Sans.

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Weight 10

WebRTC address exposure

Checks ICE candidates for additional network addresses. This is an environment-risk signal, not direct location proof.

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Weight 10

Chinese browser / WebView

Checks User-Agent and Client Hints for WeChat, QQ, UC, Quark and similar identifiers.

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Weight 8

Device vendor

Checks UA and high-entropy Client Hints for HarmonyOS, Huawei, Xiaomi, OPPO and related device signals.

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Weight 6

Intl locale

Reads the locale selected by the browser's date formatter.

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Weight 4

Timezone offset

Checks whether local time is offset from UTC by eight hours.

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Weight 3

Emoji platform style

Infers the emoji rendering platform from OS and browser identifiers; this is only a weak correlation.

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Weight 3

Interpretation and privacy

This is not an Anthropic product and cannot inspect the complete Claude Code runtime. It estimates similarity from browser-visible signals and must not be treated as a definitive account, ban or regional-eligibility decision.

All analysis runs locally except that the WebRTC item contacts a public STUN service to collect ICE candidates. Results are not submitted to the NexScan API.

Detection concepts reference the open-source project LinXiaoTao/FuckClaude · MIT License