What Is an A Record?
An A record (Address record) is a DNS entry that maps a domain or subdomain to an IPv4 address, telling the internet which server hosts the website for that name. When someone visits your domain, DNS uses the A record to convert the human-friendly name into the numeric IP address a browser needs to connect. It is one of the most fundamental DNS records; without a correct A record, a domain cannot point visitors to a website.
- Full name
- Address record
- Maps to
- An IPv4 address (e.g. 192.0.2.10)
- IPv6 equivalent
- AAAA record
- Defined in
- DNS standards (IETF RFC 1035)
What is an A record? #
An A record, short for Address record, is the DNS entry that connects a domain name to the IPv4 address of the server hosting its website. Computers do not understand names like yourbusiness.com, they communicate using numeric IP addresses such as 192.0.2.10. The A record bridges that gap, storing the mapping so that when a visitor's device asks where your domain lives, DNS answers with the IP address from your A record and the browser connects to that server. It is one of the oldest and most essential record types in the Domain Name System. Nearly every website depends on at least one A record, typically one for the bare domain and one for the www version. If the A record is missing or wrong, visitors cannot reach your site even if the server itself is running perfectly. For how records fit into the wider lookup process, see /wiki/what-is-dns, and for hands-on DNS management, see /services/domains-dns-email.
How does an A record work? #
When someone types your domain into a browser, a chain of DNS lookups begins. The browser asks a resolver, which walks up to your domain's authoritative nameservers and requests the A record for the name. The nameserver responds with the IPv4 address stored in that record, and the browser then opens a connection to that IP to fetch your website. Resolvers cache the answer for a period defined by the record's TTL (time to live), so repeat visits skip the full lookup and load faster. The A record itself is simple: a name (like the domain or a subdomain), the record type A, and the IPv4 address it points to, plus a TTL. That simplicity belies its importance, this one mapping is what makes your domain usable. The nameservers that hold your A record are explained on /wiki/what-is-a-nameserver, and you can point a domain at new hosting by updating this record, which we handle during moves via /services/website-migrations.
A record vs AAAA record #
The A record handles IPv4 addresses, the older, most widely used version of internet addressing, written as four numbers like 192.0.2.10. The AAAA record (pronounced quad-A) does the same job for IPv6 addresses, the newer, much larger address space written as longer hexadecimal strings like 2001:db8::1. As the internet runs low on IPv4 addresses, IPv6 adoption grows, so many domains now publish both an A record and an AAAA record, letting devices connect over whichever protocol they support. For a typical local business website, the A record remains the essential one, but adding an AAAA record ensures IPv6-only clients can still reach you and is increasingly considered good practice. The two records coexist without conflict; a browser simply picks the address family it can use. We configure both where hosting supports IPv6, as part of a modern DNS setup through /services/domains-dns-email, so your site is reachable to the widest possible audience.
A record vs CNAME record #
These two are often confused because both can point a name somewhere, but they work differently. An A record maps a name directly to an IPv4 address, a fixed number. A CNAME (Canonical Name) record instead points one name to another name, creating an alias, see /wiki/what-is-a-cname-record. For example, www.yourbusiness.com might be a CNAME pointing to yourbusiness.com, which in turn has an A record pointing to the actual IP. The practical rules matter: a CNAME cannot be used on the root (bare) domain in classic DNS, and a name with a CNAME cannot also have other records, so the root domain almost always needs an A record. CNAMEs shine when pointing subdomains at third-party services whose IPs may change, because you alias to their name and they manage the underlying address. Choosing correctly between A and CNAME avoids errors, and we set these up properly for clients, verifying the result with tools on /services/domains-dns-email.
Why is the A record important for your website? #
The A record is the link that makes your domain actually load a website. Without it, or with an incorrect one, visitors typing your domain get an error, no matter how good your site or how fast your server. It is also central to moving your site: when you change web hosts, you update the A record to point at the new server's IP address, which is what redirects traffic to the new home. Because the A record controls where your main domain resolves, mistakes here cause the most visible outages, an entire site going dark. It also interacts with SSL certificates and CDNs, since those services need the domain to resolve to the right place to work, see /wiki/what-is-an-ssl-certificate. Getting the A record right, and updating it carefully during changes, is foundational to uptime and reachability, see /wiki/what-is-website-uptime. We treat it as a critical checkpoint in every launch and migration via /services/website-migrations.
A records, subdomains, and multiple addresses #
A records are not limited to your main domain. Each subdomain, like shop.yourbusiness.com or app.yourbusiness.com, can have its own A record pointing to its own server, letting you host different services on different machines under one brand. This is common when a store, blog, or web app lives separately from the main site, see /services/web-app-development. You can also create multiple A records for the same name, each pointing to a different IP address, a simple way to distribute traffic across several servers, a basic form of load balancing and redundancy. Resolvers then hand out the addresses in rotation. While more advanced setups use dedicated load balancers, multiple A records offer a lightweight option for spreading load or providing failover. Planning your A records thoughtfully lets a growing business run several services cleanly under one domain. We map out this structure during projects and manage it through /services/domains-dns-email, keeping subdomains and services organized.
Common A record mistakes #
A handful of errors cause most A-record problems. The most frequent is pointing the record at the wrong or outdated IP address, often after a host change, so the domain loads the old server or nothing at all. Another is forgetting to create both the root and www records, so one version of the site works and the other fails. Editing the A record at the wrong provider, one whose nameservers are no longer authoritative, means changes appear to do nothing, see /wiki/what-is-a-nameserver. Setting an excessively long TTL right before a planned change makes propagation drag on, while people often forget that any change needs time to spread worldwide, see /wiki/what-is-dns-propagation. Finally, missing SSL or CDN adjustments after repointing can break secure loading. Each of these is avoidable with a checklist and careful sequencing, lowering TTLs ahead of a move, verifying the authoritative provider, and confirming both records. We follow exactly that process on every migration.
How do you set up or change an A record? #
You manage A records wherever your domain's DNS is hosted, at your registrar, your web host, or a dedicated DNS provider, in the DNS management or zone-editor area. To create one, you enter the name (the domain, www, or a subdomain), select record type A, provide the IPv4 address of your server, and set a TTL. To repoint a site to new hosting, you edit the existing A record's IP address to the new server's address. Because the change propagates gradually, plan around the TTL: lower it a day before a move so the switch takes effect quickly, then restore a longer TTL afterward for efficiency, see /wiki/what-is-dns-propagation. Always confirm you are editing records on the authoritative nameservers. After a change, verify the domain resolves to the new IP and that the site loads over HTTPS. We handle A-record setup and changes for clients through /services/domains-dns-email and during launches and moves via /services/website-migrations.
A records and hosting, email, and SEO #
A records tie your domain to hosting, and their reliability affects both availability and search performance. If the A record points to a fast, reliable server, visitors and search crawlers reach your site quickly; if it points to a slow or down server, both suffer. Uptime and speed are signals that influence rankings and user experience, so a correctly configured A record on solid hosting is part of the SEO foundation, see /wiki/website-speed-guide and /wiki/what-is-website-uptime. While the A record handles web traffic, remember that email uses separate MX records, so changing where your website points does not automatically move your email, a distinction that prevents accidental mail outages, see /wiki/what-is-an-mx-record. Coordinating web and email records during any change keeps the whole domain working. We keep these aligned and pair the right hosting with performance work from /services/speed-optimization, so the address your A record points to is worth reaching.
FAQ
What does an A record do?
An A record maps a domain or subdomain to an IPv4 address, telling browsers which server hosts the website for that name. When someone visits your domain, DNS uses the A record to translate the name into the numeric IP address a browser needs to connect. Without it, the domain cannot load a website.
What is the difference between an A record and a CNAME?
An A record points a name directly to an IPv4 address (a number). A CNAME points one name to another name, creating an alias. Root domains typically need an A record because CNAMEs cannot be used there, while subdomains often use CNAMEs to point at third-party services. See /wiki/what-is-a-cname-record.
What is the difference between an A record and an AAAA record?
An A record maps a name to an IPv4 address (like 192.0.2.10), while an AAAA record maps a name to an IPv6 address (like 2001:db8::1). Many domains publish both so devices can connect over whichever protocol they support. The A record remains the essential one for most sites.
How long does an A record change take to work?
It can take anywhere from a few minutes to 48 hours, depending on the record's TTL and how long resolvers cache the old value. Lowering the TTL a day before a planned change makes the switch take effect faster. This delay is called DNS propagation, see /wiki/what-is-dns-propagation.
Do I update the A record to change web hosts?
Yes. Moving to a new host usually means updating the A record to point at the new server's IP address. Do this carefully, lower the TTL beforehand and verify the site loads over HTTPS afterward. Our /services/website-migrations team handles this so the switch happens without downtime.
Does changing my A record affect email?
No, not directly. Email is routed by MX records, which are separate from the A record. Changing where your website points does not move your email. This separation prevents accidental mail outages, but it also means you must manage web and email records together during any change, see /wiki/what-is-an-mx-record.
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