DNS turns names like example.com into the addresses and settings that websites and email depend on. These tools query live DNS, so you see exactly what resolvers return right now: useful when you move a site, switch email providers, or chase a "site can't be reached" error.
| I want to… | Use |
|---|---|
| Check whether a DNS change has reached resolvers around the world | DNS Propagation Checker |
| See every record a domain publishes in one go | DNS Lookup |
| Find the IP address a website points to | A Lookup (IPv4), AAAA Lookup (IPv6) |
Check where a subdomain such as www is aliased | CNAME Lookup |
| Find out which DNS provider controls a domain | NS Lookup |
| Confirm a site-verification or SPF TXT record is published | TXT Lookup |
| Find the hostname behind an IP address | Reverse DNS Lookup |
| See who a domain is registered with and when it expires | WHOIS Lookup |
| Check a domain's mail servers, SPF, DKIM or DMARC | Email tools |
| Record | What it holds | Example value |
|---|---|---|
| A | The IPv4 address for a name | 203.0.113.10 |
| AAAA | The IPv6 address for a name | 2001:db8::10 |
| CNAME | An alias pointing to another hostname | example.com. |
| MX | A mail server for the domain, with a priority (lower is tried first) | 10 mail.example.com. |
| NS | A name server that is authoritative for the domain | ns1.example.net. |
| TXT | Free text: SPF, DKIM and DMARC policies, verification tokens | "v=spf1 include:_spf.example.net ~all" |
| PTR | The hostname for an IP address (reverse DNS) | mail.example.com. |
| SOA | The zone's primary name server, admin contact, serial number and timers | ns1.example.net. hostmaster.example.com. 2026100201 … |
| SRV | Host and port for a service, with priority and weight | 10 5 5060 sip.example.com. |
| CAA | Which certificate authorities may issue certificates for the domain | 0 issue "letsencrypt.org" |
SOA, SRV and CAA records can be queried with the DNS Lookup tool by choosing the record type.
www instead of the apex, or the reverse) are common.ipconfig /flushdnssudo dscacheutil -flushcache; sudo killall -HUP mDNSResponderresolvectl flush-cachesMoving to new name servers usually takes the longest to settle: resolvers cache the delegation published by the domain's top-level domain (for .com that TTL is 48 hours), and you can't shorten it from your own DNS settings.