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CNAME Lookup

A CNAME lookup follows an alias from the name you enter through each hop until the chain stops.

This check runs on our server. The address you enter is used only for this check and is not stored.
Updated

This check runs on our server. The address you enter is used only for this check and is not stored.

How to use the CNAME Lookup

  1. Enter the alias, often a hostname such as www.example.com.
  2. Pick a resolver.
  3. Tick the robot check and press Look up.
  4. The first row is the direct target. If that target is also a CNAME, the chain lists the rest.

How it works

This check runs on our server. The hostname is not stored.

A CNAME says "this name is an alias of that name." The tool queries CNAME, then queries the target, and keeps going until a name has no CNAME or eight hops have been followed. A loop, the same name twice, stops the walk. The apex of a zone (example.com itself) is not supposed to be a CNAME. If a resolver still returns one, it is shown.

Examples

  • www.example.com CNAME example.com is a one-step chain. example.com has no further alias, so the walk stops.
  • A CDN name can be three hops: your host, a vendor hostname, then another vendor hostname.
  • A name that is only an A record, with no CNAME, returns "The domain has no CNAME records."

Limitations

  • The chain stops at eight hops.
  • ALIAS and ANAME records used by some DNS hosts are not CNAME. They will not appear here.
  • The final target's A or AAAA addresses are on the A and AAAA pages, not in this chain.

Frequently asked questions

Can the root of a domain be a CNAME?

Standard DNS does not allow a CNAME on the zone apex next to NS and SOA. Hosts such as www can be CNAMEs. Some providers fake an apex alias with a different record type.

What is a CNAME loop?

A points at B and B points at A. The lookup stops when a name repeats, so the page does not chase it forever.

Does a CNAME replace the other records?

On that exact name, yes. A name that is a CNAME should not also have its own A or MX. The target name holds those.

Often used together with the CNAME Lookup.

  • NS Lookup

    Name servers from the NS records, with TTL.

  • DNS Lookup

    One table of A, AAAA, MX, NS, TXT, SOA, and CAA records for a domain.