Signals commonly visible to a web page
| Category | Examples | Use in this check |
|---|---|---|
| Network | Exit IP, country, ASN, network type | Region, proxy, and hosting indicators |
| Locale | Timezone, UTC offset, language, Intl locale | Obvious consistency conflicts |
| Browser | User agent, version, platform, automation traits | Compatibility and environment context |
| Graphics and device | Screen, CPU, memory, canvas, WebGL | Supporting context without a stored fingerprint |
Data a normal web page cannot reliably read
- Claude account history, official blacklists, or real enforcement scores.
- Payment card details, billing review, or platform subscription records.
- OS account region, a complete installed-app list, or other application data.
- Precise GPS location without permission.
- Whether an email inbox previously contained tracking pixels or probes.
Why language, fonts, and emoji remain weak signals
Language, fonts, and locale formats may reflect personal preference, work, or a multilingual environment. FK Claude shows these browser-visible traces but does not raise the overall result to medium or high solely because of Chinese language, a local CJK font, or emoji differences.
How this site limits data use
The check runs for the current page session. It does not store a canvas image or stable fingerprint hash and does not request precise location. Network details require external lookup services; see the privacy notice for the data flow and email-unlock fields.
Check the current browser environment
Return to FK Claude and review 21 browser-visible signals for free. The result is a self-check reference only.
Start the check