// 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 and CNAME over encrypted DoH.
- · Cloudflare / Google / DNS.SB
- · Per-provider latency
- · Inline reverse DNS
SPF, DMARC, DKIM, BIMI and 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.