Points a name at an IPv4 address.
An A record maps a name to one 32-bit IPv4 address. A name can have several A records; resolvers return them all and clients usually try them in turn, which is the simplest form of load spreading.
- Type
- A
- Code
- 1
- Defined in
- RFC 1035
- IANA description
- a host address
- Field: Address
- Dotted-quad IPv4 address, e.g. 192.0.2.10
How it works
Your website’s apex (example.com) and www name normally have A records, either set directly or through a provider’s “flattening” of an alias. Mail servers named in MX records need A or AAAA records too: an MX must point at a host name that has address records, never at an IP address itself.
Example
www.example.com. 3600 IN A 192.0.2.10
Example uses reserved documentation names and addresses (RFC 2606, RFC 5737, RFC 3849).
Common mistakes
- Putting an A record and a CNAME on the same name (a CNAME must stand alone).
- Forgetting www when moving hosts, so one of example.com and www.example.com still points at the old server.
- Leaving a long TTL before a planned move: lower it a day ahead, after the old TTL has had time to expire.
How to check yours
To check it, look up A for both the apex and www after any hosting change; the values should be the new server’s address. A stale answer from a resolver that cached the old one fades out once the record’s TTL expires.
For email
SPF’s a mechanism and the fallback for domains without MX both read A records.
Related record types
Sources
Sources
- IANA: Resource Record (RR) TYPEs registry · checked 5 Oct 2026
- RFC 1035 · checked 5 Oct 2026