What Is an A Record (Address Record)?
An A record is the most fundamental DNS record type. It maps a domain name or hostname to an IPv4 address, telling browsers and applications where to find your server.
How A Records Work
When you type a domain name into your browser, the DNS resolver queries the domain's authoritative nameserver for an A record. The nameserver responds with the IPv4 address associated with that hostname. The browser then uses that IP address to connect to the web server and load the page.
Each A record has a TTL (Time to Live) value that determines how long DNS resolvers cache the result. A shorter TTL means changes propagate faster but generate more DNS queries. A typical TTL is between 300 seconds (5 minutes) and 86400 seconds (24 hours).
Why A Records Matter
A records are required for any domain that needs to be accessible on the internet. Without an A record (or AAAA for IPv6), a domain cannot resolve to a server. A records are also used indirectly in email delivery — when an MX record points to a mail server hostname, that hostname must have an A record to be reachable.
Frequently Asked Questions
What is the difference between an A record and an AAAA record?
An A record maps to an IPv4 address (e.g., 93.184.216.34), while an AAAA record maps to an IPv6 address. Both resolve hostnames to IPs, just for different IP versions. Most domains have both for maximum compatibility.
Can I have multiple A records for the same domain?
Yes. Multiple A records for the same hostname is called DNS round-robin. It provides basic load balancing across servers, though it does not offer health checking or automatic failover.
How long does it take for A record changes to propagate?
Propagation depends on the TTL value. A TTL of 300 means resolvers cache the record for 5 minutes. Lowering the TTL before making changes speeds up propagation. Typical propagation takes minutes to hours.