Glossary / A record

A record (DNS address record)

An A record (address record) maps a domain name to a server's IPv4 address, for example example.com to 185.91.72.34. It is what tells the browser which server to reach when someone opens your site. Without a correct A record, the domain leads nowhere.

When you type a domain into a browser, your computer first asks DNS a simple question: "what is the IP address for this name?" The A record is the answer - it holds a single IPv4 address in the form 185.91.72.34.

One domain can have several A records pointing to different IPs, which spreads load across servers. Subdomains like www, shop, or blog have their own A records or point to the main domain through a CNAME.

After you change an A record it needs time to propagate: the old value stays in caches until the TTL runs out, so the site may resolve differently for different people for a few hours.

Example

example.com.  3600  IN  A  185.91.72.34

Common mistakes

• Confusing an A record (IPv4) with an AAAA record (IPv6); they are separate records for separate IP versions.
• Putting a hostname instead of an IP address in the A record; A only accepts a numeric IPv4 value.
• Expecting an instant change after editing and forgetting about TTL and DNS caching.
• Leaving the old A record pointing at the previous host after a migration, so some visitors land on a dead server.

Related terms

• AAAA record AAAA record (DNS IPv6 record)
• CNAME record CNAME record (DNS alias)
• MX record MX record (mail exchanger)
• TXT record TXT record (DNS text record)
• NS record NS record (name server record)