Claude China — Independent Environment Check

Claude China is an independent, read-only network and browser environment diagnostic tool. Check on demand to see the public IP visible to one HTTPS endpoint, estimated country/region, network organization and ASN, and network timezone. See your browser's timezone, UTC offset, languages, Intl locale and browser/platform information alongside it. Compare timezone identifiers and optional public WebRTC ICE candidates of the same IP family to the HTTP-visible IP. Missing results, timeouts and IPv4/IPv6 ambiguity are unavailable or inconclusive. Differences are observations, never account-risk scores. One compact local summary enables comparison with the previous manual check. Raw IPs and candidate addresses are not saved, so address changes are not tracked. The summary expires after 30 days and is deleted on next open. Clear local data at any time. Claude Availability references a dated, bundled copy of Anthropic's public Claude.ai country list, showing the source, verification date and regional exceptions. It does not establish account eligibility or predict restrictions. Not affiliated with or endorsed by Anthropic. Privacy before you check: a network lookup sends your IP and standard request metadata to GeoJS (get.geojs.io). Optional WebRTC contacts Cloudflare STUN, which sees that route's source IP. Providers have their own privacy policies. No account, analytics, advertising or background monitoring; no website content, cookie or browsing-history access. Browser observations and comparisons stay local. Service failures are explicit; no automatic retry. Original animated mascot, reduced-motion support, Chinese/English, light/dark/system themes, keyboard controls and expandable explanations. No settings modification, protection guarantees or circumvention tools. Support/privacy: jackmac2077@gmail.com