// about ldns

One URL,
every domain tool.

LDNS is a free toolkit for inspecting any domain on the internet — DNS records, registration data, email authentication, TLS certificates, security headers, IP geolocation, and subdomains. No accounts. No tracking. Edge-cached on Cloudflare so lookups are fast.

// what's in the box

Six tools, one workflow.

01 —

DNS Records

A, AAAA, MX, TXT, NS, SOA, CAA, CNAME — over encrypted DoH with per-provider latency.

02 —

RDAP & WHOIS

Registration data, registrar, expiry, DNSSEC. WHOIS fallback for ccTLDs that don't support RDAP.

03 —

Email security

SPF, DMARC, DKIM, BIMI, MTA-STS — provider detection, policy explanation.

04 —

Server response

Headers, redirect chain, TTFB, tech-stack badges, IP/ASN/country per upstream.

05 —

TLS & security

Cert from CT logs, response security headers, HSTS preload, well-known files.

06 —

Subdomains

Discovery via Certificate Transparency logs, deduplicated and exportable as CSV.

// how to use it

Just put the domain in the URL.

All DNS records:

ldns.com/google.com try it →

Add a tool slug for a focused view:

ldns.com/google.com/email try it →

Hash fragments deep-link to specific sections:

ldns.com/google.com/email#dmarc try it →

// how it's built

Edge-rendered, cache-first, no database.

DNS queries go straight to public DoH resolvers (Cloudflare, Google, DNS.SB). Server probes, TLS, ASN, subdomain and email lookups run through SvelteKit endpoints that proxy to public services and cache aggressively at the Cloudflare edge.

We don't run a database. We don't track users. Every lookup is a stateless GET against a cached endpoint — that's why the same lookup is essentially free at scale, and why every page is also a public API.

Look up a domain