Look up every DNS record type for a domain at once, check propagation across Cloudflare, Google, OpenDNS, and Quad9, audit SPF/DKIM/DMARC email security with a 0-100 score, and pull WHOIS registration and SSL certificate details — all free, with no API key.
Enter a domain above and press Lookup to see its DNS records.
Diagnosing a DNS or email deliverability problem usually means bouncing between three or four separate sites — one for a basic record lookup, another (like dnschecker.org) for propagation status across resolvers, a third (like mxtoolbox.com) for SPF/DKIM/DMARC analysis, and a fourth for WHOIS. This tool combines all of it into one page organized into four tabs — DNS Records, Propagation, Email Security, and WHOIS — so a full diagnostic pass on a domain takes one lookup instead of four separate ones across different sites with different UIs and different quirks.
Every record type — A, AAAA, CNAME, MX (with priority), NS, TXT, SOA, and CAA — is queried in parallel directly against Cloudflare's 1.1.1.1 resolver using DNS-over-HTTPS, a modern, encrypted transport for DNS queries defined in RFC 8484. As a bonus, once the domain's primary A record is known, the tool automatically performs a reverse PTR lookup on that IP address, which is a useful (if often overlooked) sanity check — a mismatched or missing PTR record can affect deliverability and is sometimes a sign of shared or generic hosting infrastructure.
The Propagation tab queries the same record, for the same domain, against four operationally independent public DNS resolvers — Cloudflare (1.1.1.1), Google (8.8.8.8), OpenDNS (208.67.222.222), and Quad9 (9.9.9.9) — each contacted directly over its own DNS-over-HTTPS endpoint using the standard binary DNS wire format (not a proxy or a single shared upstream), so each answer genuinely reflects what that resolver currently has cached or has freshly resolved from the authoritative nameservers. When all four return an identical set of values, the tool marks the record as fully propagated; when even one disagrees, it's marked as still propagating, with each resolver's individual answer shown so you can see exactly where the difference lies.
SPF, DKIM, and DMARC work together as complementary layers, not substitutes for each other — SPF authorizes which servers may send mail for a domain, DKIM cryptographically signs outgoing messages so receivers can verify they weren't altered in transit, and DMARC ties the two together with a policy telling receivers what to do when a message fails both checks and, critically, provides a reporting mechanism (via the rua tag) so domain owners can actually see abuse attempts happening in their name. The Email Security tab parses each of these independently, flags specific, actionable issues (an SPF record with too many lookups, a DMARC policy stuck at 'none', a missing 'all' mechanism), and rolls everything into a single 0-100 score so you can gauge overall email authentication maturity at a glance before diving into the specifics.
The WHOIS tab performs a genuine WHOIS protocol query — first asking IANA (or a small built-in table of common TLDs, for speed) which registry server is authoritative for the domain's TLD, then querying that server directly, and following the referral to the domain's actual registrar WHOIS server for the fullest detail available — the same referral chain a command-line whois client follows. Alongside the parsed registration data (registrar, creation and expiry dates with a days-remaining countdown, name servers, and status codes), it separately connects to the domain's live website to read its current SSL certificate (issuer, validity window, expiry) and inspect response headers and page markup for recognizable server and CMS signatures, giving you both the paperwork and the technical reality of a domain in one place.
Every lookup in this tool is read-only and queries only publicly available data sources — public DNS resolvers, public WHOIS servers, and the target domain's own public-facing website — the same information any of those systems would return to anyone else asking. Nothing about the domains you look up is stored by this tool; each request is made fresh, server-side, when you press Lookup.
DNS Lookup pairs naturally with these developer tools for networking, request debugging, and SEO investigation.