WHOIS Viewer

Shows WHOIS (RDAP) information for the domain/IP of the page you're currently viewing.

WHOIS Viewer is a simple lookup tool that shows WHOIS/RDAP information, hosting/country info, and site technology details for the domain or IP address of the page you're currently viewing — all in one click. ■ Key Features ・WHOIS / RDAP Information Shows registration date, last updated date, expiration date, registrar, registrant, and name servers. For TLDs not supported by RDAP (e.g. .jp), it automatically falls back to WHOIS-based alternative APIs or JPRS WHOIS. ・Hosting / Country Information Resolves the domain's IP address via DNS and shows the hosting organization/ISP, ASN, country/region, and timezone. ・Site Information (CMS / CDN / SSL Certificate) Automatically detects the CMS or e-commerce platform the site is built on, and estimates the CDN provider it uses. Looks up Certificate Transparency (CT) logs to show the SSL certificate issuer (CA) and validity period. ・Caching WHOIS and site info results are cached locally for 24 hours, so revisiting a page loads instantly (a Reload button lets you force a refresh). ・History Keeps a local history of up to 20 domains/IPs you've looked up, so you can quickly reopen any of them from a list. Nothing is ever sent externally. ・Customizable Layout The "WHOIS", "Hosting/Country", "Site Info", and "My Info" sections can be reordered by drag-and-drop, and each section can be shown or hidden from a settings screen. ■ Who is this for? ・Web developers/operators who want to quickly check domain details for clients or competitor sites ・Engineers who want a quick look at a site's infrastructure (CDN/certificate) ・Anyone who wants to check the registration details of a suspicious-looking site ■ About Privacy This extension never collects or transmits your browsing history to any external server. Only the domain/IP address of the currently viewed tab is sent to public WHOIS/DNS/IP-geolocation APIs in order to display results. Your WHOIS history and cache are stored only inside your own browser (`chrome.storage.local`) and are never uploaded anywhere. See the Privacy Policy for details.