// dns · rdap · email · server · security
Look up any domain
in one place.
DNS records, registration data, email authentication, TLS certificates, security headers, IP geolocation, and subdomains — for any domain on the internet. No accounts. No tracking.
// try ldns.com/google.com, /cloudflare.com, or /github.com
$ ldns google.com
// what's in the box
Five tools, one URL.
Records
A, AAAA, MX, TXT, NS, SOA, CAA, CNAME — over encrypted DoH.
- · Cloudflare / Google / DNS.SB
- · Per-provider latency
- · Inline reverse DNS
SPF, DMARC, DKIM, BIMI, MTA-STS — with provider detection.
- · DKIM probes 22 selectors
- · 40+ provider patterns
- · Policy explanations
Server
Headers, redirect chain, response time, tech stack.
- · HTTP/3 detection
- · Tech-stack badges
- · Per-IP ASN + country
Security
TLS cert, security headers, HSTS preload, well-known files.
- · Cert from CT logs
- · Headers audit
- · security.txt + robots.txt
Subdomains
Discover subdomains via Certificate Transparency logs.
- · Edge-cached crt.sh
- · Live filter + CSV export
- · Deduplicated, sorted
// developer api
Every tool is also an API.
Free, public, rate-limited JSON endpoints powering the same lookups you see in the UI. No API key. No accounts. Heavy edge caching at Cloudflare so your lookups are fast.
GET /api/server?domain=…
GET /api/tls?domain=…
GET /api/asn?ip=…
GET /api/security/headers?domain=…
GET /api/subdomains?domain=…
GET /api/dkim?domain=…
// browser extension
One click on any tab.
The LDNS extension for Chrome and Firefox runs the same lookups as this site, on whatever tab you're viewing — popup or pinned in the side panel.