What Is an A Record in DNS?

TL;DR
An A record (Address record) is the most common DNS record type. It maps a domain name (e.g. example.com) directly to an IPv4 address (e.g. 93.184.216.34), telling browsers and applications where to find the server.

How A Records Work

When you enter example.com in a browser, the DNS resolver queries for the A record and receives the IPv4 address. The browser then connects to that IP to load the website. A records support:

• Root domains (example.com)
• Subdomains (www.example.com, api.example.com)
• Multiple IPs for basic load balancing (round-robin)

Common Use Cases

• Website hosting: pointing domains and www to web servers
• Load balancing: multiple A records to distribute traffic
• CDN integration: pointing to edge server IPs
• Subdomain routing: different services (API, mail, blog) to different servers
• Email & API resolution: locating mail servers or API endpoints

How to Lookup A Records

dig example.com A

nslookup -type=A example.com

Record Format

NAME          TTL    CLASS  TYPE  VALUE
example.com.  3600   IN     A     192.0.2.1

• NAME: domain or subdomain (trailing dot = FQDN)
• TTL: time to live in seconds (how long resolvers cache it)
• TYPE: A
• VALUE: valid IPv4 address only

Valid Examples

example.com.      A   93.184.216.34
www.example.com.  A   93.184.216.34
api.example.com.  A   198.51.100.10

Comparing different types of records

Frequently Asked Questions

References

Related DNS Record Types

• AAAA Record: Maps domains to IPv6 addresses
• CNAME Record: Creates domain aliases
• NS Record: Specifies name servers