DNS Lookup

How to Use

1. Enter a domain — bare hostname, full URL, or trailing-dot form all work; the tool normalises automatically.
2. Pick a record type. ALL fans out parallel queries for A, AAAA, CNAME, MX, TXT, NS, SOA, and CAA in one click.
3. Pick a resolver: Cloudflare (1.1.1.1) or Google (8.8.8.8).
4. Click Lookup or press Enter.
5. Switch between Records, Raw (dig-style output), and JSON (raw DoH response) tabs.

Record types supported

• A — IPv4 address.
• AAAA — IPv6 address.
• CNAME — canonical alias pointing at another name.
• MX — mail exchanger with priority.
• TXT — arbitrary text. Hosts SPF, DKIM, DMARC, domain verification, and HTTP/3 origin signals.
• NS — authoritative name servers for the zone.
• SOA — Start of Authority: primary NS, contact, serial, refresh timers.
• CAA — which Certificate Authorities may issue for the domain.
• PTR — reverse DNS. Query the x.y.z.w.in-addr.arpa name yourself; the tool issues a plain PTR query.
• SRV — service location with priority, weight, port, and target.

Why DNS-over-HTTPS

Browsers cannot open raw UDP/53 sockets, which is why no in-browser tool can speak classic DNS. DoH wraps DNS messages in HTTPS, so a regular fetch() call can ask a public resolver for any record. Cloudflare and Google both expose a JSON profile (application/dns-json for Cloudflare, native JSON for Google) with permissive CORS — this tool does nothing more than call those endpoints and render the response.

Reading the summary pills

• NOERROR / NXDOMAIN / SERVFAIL — the DNS RCODE. NXDOMAIN is a valid answer meaning “domain does not exist”; SERVFAIL means the resolver could not answer.
• N records — how many answer records came back. Zero with NOERROR means the type exists for the zone elsewhere but not for the requested name.
• DNSSEC ✓ — the AD flag is set. The resolver validated signatures.
• Resolver — which DoH endpoint served the response.
• Latency — round-trip time from fetch() start to JSON parse.

Typical use cases

• Verifying that an A or CNAME change has propagated past a specific resolver.
• Confirming MX, SPF (TXT), DKIM (TXT), and DMARC (TXT) before launching a new sending domain.
• Comparing the records two public resolvers see — Cloudflare vs Google can disagree during a propagation window.
• Checking CAA before issuing a certificate to avoid the “CAA mismatch” failure mode.
• Sanity-checking NS delegation when moving zones between registrars.

Limits by design

This is a single-shot resolver client. It does not perform automatic ARPA conversion for reverse IP lookups (input the in-addr.arpa name yourself for PTR), it does not query authoritative servers directly (it asks a public recursive), and it does not run history, WHOIS, blocklist, or propagation comparisons across many resolvers. For propagation maps use whatsmydns.net; for authoritative-only lookups use dig @ns1.example.com locally.

Related tools on ZeroTool

• HTTP Header Analyzer — once DNS resolves, inspect what the server returns.
• SSL Certificate Decoder — pair DNS with the certificate served at the resolved IP.
• URL Parser — break a URL into its components before looking up the hostname.
• IP Subnet Calculator — once you have the A/AAAA, derive subnet structure.