DNS lookup
Look up A, AAAA, MX, CNAME, TXT, and NS records for a public domain—what the internet’s name system publishes right now.
What DNS lookup is for
DNS is the phone book of the internet: it maps names like www.example.com to IPv4/IPv6 addresses, mail routes (MX), name servers (NS), proofs (TXT), and aliases (CNAME). When email bounces, HTTPS fails after a migration, or a subdomain “works for some people,” DNS is often the first place to look.
Modern assistants and developers phrase questions as “what records does this domain publish?” or “is this TXT/SRV present?” This tool answers with the records our resolver sees right now—not a cached historical snapshot.
It helps validate cutovers (new host, new mail provider), debug TTL and propagation, and confirm that public authoritative data matches what you expect.
How this tool works
Short technical summary of what runs on our servers when you click the button.
We query common record types (A, AAAA, MX, TXT, NS, CNAME) using Node’s DNS APIs from the same environment as our other tools. Results reflect what our infrastructure would use when connecting outbound.
You get a fresh lookup each run. If your registrar or DNS host just changed records, waiting for TTL expiry is still a factor—but you are not looking at a stale dashboard screenshot.
We block obviously internal-only suffixes and patterns so the tool stays appropriate for public diagnostics, not scanning your LAN.
More BuildSpace tools
All utilities run from our infrastructure with the same safety limits. No account required.
- Site statusSee if a URL responds from our servers—outage vs. local issue.
- HTTP header checkerStatus code, full response headers, and common security headers.
- SSL certificate checkerCertificate subject, issuer, validity, fingerprint, and SANs.
- Ping & response timeThree-run DNS, TCP, and HTTP timing breakdown (no ICMP).
- WHOIS (RDAP)Registrar and registration data via RDAP where available.
- Website speed testTTFB, sampled bytes, Content-Length, and encoding hints.
- Open port checkerTCP connect test to a host and port from our network.