# A record An A record connects a name, such as example.com or www.example.com, to the IPv4 address of the server that answers for it. It is the most common DNS record: when you type a website's name, an A record is usually what tells your browser where to go. - Record type: A - Type number: 1 - Used for: Websites - How common: Everyday - Defined in: RFC 1035 ## Format ``` IN A ``` | Field | What it means | Accepted values | | --- | --- | --- | | Name | The name being pointed. `@` is the domain itself; `www` is www.example.com. | A host name. Letters, digits and hyphens, up to 63 characters between dots and 253 in total. `*` for a wildcard. | | TTL | How long resolvers may keep the answer before asking again. | Seconds. 300 to 3600 is typical; many DNS hosts offer Auto. | | Address | The server's IPv4 address. | Four numbers from 0 to 255 separated by dots, such as `192.0.2.10`. No port, no `http://`, no name. | ## Examples ### The domain itself ``` @ 3600 IN A 192.0.2.10 ``` example.com goes to 192.0.2.10. ### A subdomain ``` app 300 IN A 198.51.100.7 ``` app.example.com goes to a different server. A short TTL makes a later move quicker. ### Several servers ``` @ 300 IN A 192.0.2.10 @ 300 IN A 192.0.2.11 ``` Two A records at the same name. Resolvers return both and clients pick one, a simple way to spread load. There's no health checking: if one server is down, some visitors still get it. ### Wildcard ``` * 3600 IN A 192.0.2.10 ``` Any name under example.com without its own records, such as anything.example.com, goes to 192.0.2.10. ## How an A record is used When a browser opens example.com, it asks a resolver (usually run by your internet provider, or a public one such as 1.1.1.1 or 8.8.8.8) for the A records of example.com. The resolver asks the domain's nameservers, caches the answer for the TTL, and hands back the address. The browser then connects to that address. A records only hold addresses. They know nothing about ports, paths or https: the web server decides which site to show using the name the browser sends. That's why many websites can share one IP address. ## A record or CNAME? Use an A record when you know the server's IP address and it rarely changes, such as your own server or a host that gives you a fixed address. Use a [CNAME](https://lemon.domains/dns-records/cname) when a service gives you a host name instead, such as `yourshop.myshopify.com` or `cname.vercel-dns.com`, so they can change their addresses without you editing anything. At the root of a domain (@) you can't use a CNAME. Use an A record with the address your host gives you, or an [ALIAS](https://lemon.domains/dns-records/alias) record if your DNS host offers one. ## TTL 3600 (one hour) suits a stable server. Drop it to 300 a day before you move servers so the change spreads in minutes, then raise it again afterwards. ## Common mistakes - Putting a name or a web address in the value. An A record takes only an IPv4 address; for a name use a CNAME. - Putting an IPv6 address in an A record. IPv6 addresses go in [AAAA records](https://lemon.domains/dns-records/aaaa). - Adding an A record at a name that already has a CNAME. A name with a CNAME can't have anything else, so most DNS hosts refuse it. - Leaving an old A record next to a new one after moving servers, so some visitors still reach the old server. - Using a private address such as 192.168.1.10 for a public website. It only works on your own network. ## At your DNS host - Cloudflare: the orange cloud (Proxied) answers with Cloudflare's addresses instead of yours, so a lookup won't show the address you entered. Grey cloud (DNS only) publishes your address as it is. - Route 53: leave Record name blank for the domain itself. For AWS load balancers and CloudFront, use an Alias record instead of a fixed address. - GoDaddy, Namecheap: type @ in Host or Name for the domain itself, and remove any parking A record the registrar added first. - Most dashboards add the domain for you: type www, not www.example.com, or you may end up with www.example.com.example.com. ## Questions ### What does an A record do? It tells the internet which IPv4 address a name lives at. When someone visits example.com, their browser looks up its A record and connects to that address. ### Can a domain have more than one A record? Yes. Several A records at the same name are all returned, and clients spread their connections between them. There's no health checking, so remove an address as soon as its server goes away. ### What does A stand for? Address. The AAAA record is the IPv6 version, named because IPv6 addresses are four times as long (128 bits instead of 32). ### How long does an A record change take to work? Up to the old record's TTL. Resolvers that cached the old address keep using it until the TTL runs out, so lower the TTL before a planned change. ## Related - [AAAA record](https://lemon.domains/dns-records/aaaa.md) - [CNAME record](https://lemon.domains/dns-records/cname.md) - [ALIAS and ANAME records](https://lemon.domains/dns-records/alias.md) - [HTTPS record](https://lemon.domains/dns-records/https.md) - [PTR record](https://lemon.domains/dns-records/ptr.md) Interactive version with a record checker and live lookup: https://lemon.domains/dns-records/a