How This DNS Lookup Tool Works
Enter a domain (or an IP address for a reverse lookup) and this dns lookup tool, a real dns query tool rather than a cached snapshot, queries a live DNS resolver and returns every A, AAAA, CNAME, MX, TXT, NS, SOA, and SRV record currently published for that domain. Unlike a plain dns checker that just dumps raw text, results land in one table you can filter by type, so an a record lookup, an aaaa record lookup, an ns lookup, or a cname lookup is just a click on its own tab, not a separate query. Every row includes a plain-English explanation, so you can check dns records without already knowing what an SOA or NS record means.
Reverse DNS Lookup (PTR Records)
A reverse dns lookup answers the opposite question from every other record type here: given an IP address, what hostname is responsible for it? This tool detects that automatically, enter an IP address (IPv4 or IPv6) instead of a domain and it runs a ptr lookup against the address's in-addr.arpa/ip6.arpa zone instead of the usual forward records. This is the standard check for confirming a mail server's reverse DNS matches its forward hostname, a mismatch there is one of the most common reasons legitimate outbound email gets flagged as spam, and it's just as useful for identifying what's actually running behind an unfamiliar IP address turning up in server logs.
Checking SPF, DKIM, and DMARC Records
Email authentication records live at underscore-prefixed subdomains, "_dmarc.yourdomain.com" for DMARC policy and "selector._domainkey.yourdomain.com" for a DKIM public key, so a proper spf record lookup or dmarc record lookup has to support querying those exact hostnames, not just the bare domain. This tool does: enter "_dmarc.example.com" and the TXT tab shows the live DMARC policy string, or check the TXT tab on the root domain to find its SPF policy directly. Combined with an mx lookup on the same domain, this covers the full set of checks needed to diagnose why outbound email is landing in spam or failing authentication.
Choosing a DNS Resolver (Google, Cloudflare, OpenDNS, Quad9)
This is effectively nslookup online, or a domain name service lookup, with a choice of which resolver actually answers the query. Pointing the same lookup at Google (8.8.8.8), Cloudflare (1.1.1.1), OpenDNS, or Quad9 instead of your system's default resolver matters because DNS changes propagate to different resolvers at different speeds, so a record you just updated might already show correctly at one public resolver while another is still serving a cached, stale answer for the rest of its TTL. It's also how split-horizon DNS setups get caught, where an internal network resolves a domain differently than the public internet, if your system default resolver returns something none of the public resolvers agree on, that's a strong signal your local network's DNS is doing something unusual.
Common Uses and Limitations
This dns checker is commonly used right after updating nameservers or dns records at a registrar, to confirm a new a record lookup or cname lookup shows the change is actually live before pointing traffic at it, or to run an mx record lookup and verify a change didn't accidentally break mail delivery. A soa lookup confirms which server is authoritative for the zone and its caching timers, while an ns lookup catches a delegation that's still pointing at an old host. One honest limitation worth knowing: this is a single live snapshot from whichever resolver you pick, not a global propagation map across dozens of locations worldwide, and it doesn't track a record's remaining TTL history or show cached vs. authoritative state, a dedicated propagation-mapping tool covers that differently.