LDNS - DNS & Domain Tools by Reparo Labs

LDNS puts a complete DNS and domain toolkit one click away: DNS records, WHOIS/RDAP registration data, email authentication, server details, and subdomain discovery. It works on the site you're already on, or any domain you type.

WHAT IT DOES

• DNS lookups over encrypted DNS-over-HTTPS, with a choice of three public resolvers and a Compare view that highlights propagation mismatches between them
• Reverse DNS and origin-network (ASN) details shown inline next to each address
• WHOIS/RDAP registration data with domain age, expiry countdown, and DNSSEC status
• Email security check-up covering SPF, DMARC, DKIM, BIMI, and MTA-STS, with the sending provider detected automatically
• Server insights: response headers, redirect-chain tracing, response time, a security-headers audit, HTTP/3 detection, and identification of the technology stack behind the site
• Subdomain discovery by scanning Certificate Transparency logs
• Click-to-copy on every value, CSV/JSON export, side-panel mode, system/light/dark theme, and deep links to full reports on ldns.com

PRIVACY

No accounts, no analytics, no tracking, no backend. Every lookup goes directly from your browser to public DNS, registry, and Certificate Transparency services. Nothing is ever sent to an LDNS server. Recent searches are stored only on your device. And you don't have to take my word for it: the source is public at github.com/jmorf/ldns. Full policy: ldns.com/extension/privacy

WHAT'S NEW

v1.8.1
• Fixed: the extension follows the tab you are on again, and the side panel now updates as you browse.
• Subdomain lookups are more reliable when crt.sh is having problems, and failures now explain what went wrong. You can add your own CertSpotter API key in Settings to remove the free-tier limit.

v1.8.0
• LDNS is now open source. The full extension and website source is at github.com/jmorf/ldns (MIT). You can read exactly what it does with your lookups.
• Removed the marketplace ("For Sale") check, with it goes the last feature that contacted an LDNS server. The extension now has no backend: every lookup goes straight from your browser to public DNS and registry services.

LINKS

Website: ldns.com
Privacy policy: ldns.com/extension/privacy
Source code and issues: github.com/jmorf/ldns
Contact: @jmorf on X