WHOIS Viewer

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

WHOIS Viewer is a simple research tool that lets you view WHOIS/RDAP details, hosting/country information, and site technical data for your current tab with a single click. ■ Key Features ・WHOIS / RDAP Information - Displays domain registration date, updated date, expiration date, registrar, registrant, name servers, and more. - For TLDs that do not support RDAP (e.g., .jp), the extension automatically falls back to WHOIS-based APIs or JPRS WHOIS. ・Hosting & Country Info - Displays hosting providers/ISPs, ASNs, country/region, and time zones based on the resolved IP address. ・Site Tech Stack (CMS / CDN / SSL Certificate) - Automatically detects major CMS and e-commerce platforms like WordPress and Shopify. - Identifies major CDNs in use, such as Cloudflare and CloudFront. - Queries Certificate Transparency (CT) logs to display the SSL certificate issuer (CA) and validity period. ・Smart Caching - Retrieved WHOIS data is cached locally for 24 hours for instant loading on repeat visits (includes a reload button to force-refresh data). ■ Recommended For ・Web developers and digital marketers who want to quickly inspect client or competitor domain details. ・Engineers needing a lightweight tool to analyze infrastructure (CDNs, SSL certificates). ・Anyone looking to check domain registration details of suspicious websites. ■ Privacy & Security This extension does NOT collect or store your browsing history on external servers. It only transmits the current tab's domain or IP address to query public APIs (WHOIS, DNS, IP geolocation, etc.). For full details, please review our Privacy Policy.