DNS records are the instructions that tell the internet where your website, email and other services live, and a single wrong record can take one of them offline.
DNS is the system that turns a domain name like example.com into the information computers need: which server hosts the website, where email should be delivered, and more. That information is stored as DNS records. If you've ever set up a website, connected email or verified a domain with a service, you've edited DNS records, even if it felt like typing mysterious values into a form.
This guide explains the most common record types in plain English. You can look up all of them for any domain with the DomainBulleter.
How many domains rely on DNS records?
Every registered domain depends on DNS records to work. According to the Domain Name Industry Brief, there were 401.6 million domain name registrations across all top-level domains at the end of the second quarter of 2026, with .com and .net together accounting for 179.1 million. Each of those needs at least nameserver records, and most also need A, MX and TXT records.
How DNS works in one paragraph
When you type a domain into your browser, your device asks a DNS resolver (usually run by your internet provider or a public service) for the domain's records. The resolver finds the domain's authoritative name servers, the servers that hold the official records, and asks them. The answer is cached for a period of time set by the record's TTL, so the next lookup is faster. That caching is why DNS changes don't appear everywhere instantly.
A records
An A record maps a name to an IPv4 address, such as 203.0.113.10.
example.com. A 203.0.113.10
This is the most basic record. It tells browsers which server to contact for the website. A domain can have several A records, which is one way to spread traffic across servers.
AAAA records
An AAAA record does the same job for IPv6 addresses, which look like 2001:db8::10. Many hosts provide both A and AAAA records so visitors on either kind of network can connect. If your host gives you an IPv6 address, it's worth adding.
CNAME records
A CNAME record makes one name an alias of another name.
www.example.com. CNAME example.com.
This says "for www.example.com, use whatever records example.com has". CNAMEs are common for subdomains that point to external services, such as a shop platform or a help desk, because the service can change its IP addresses without you updating anything.
Two rules to remember:
- A name with a CNAME shouldn't have other records alongside it.
- The root of a domain (
example.comitself) traditionally can't be a CNAME. Some DNS providers offer workarounds with names like ALIAS, ANAME or CNAME flattening.
MX records
MX records tell the world which servers accept email for a domain.
example.com. MX 10 mail1.example.net.
example.com. MX 20 mail2.example.net.
The number is the priority. Lower numbers are tried first. If you use a hosted email service, it will tell you exactly which MX records to add. Old MX records left behind from a previous provider are a common cause of lost email, so remove them when you switch.
TXT records
TXT records hold text. That sounds vague because it is: they're used for many different purposes, including:
- Domain verification for services like search consoles and email platforms
- SPF, which lists the servers allowed to send email for your domain
- DKIM, which publishes keys used to sign your outgoing email
- DMARC, which tells receivers what to do with email that fails checks
Email-related TXT records are important enough to deserve their own guide: SPF, DKIM and DMARC: How to Check Your Email DNS.
NS records
NS records list the authoritative name servers for a domain, the servers that hold its official records.
example.com. NS ns1.dnsprovider.com.
example.com. NS ns2.dnsprovider.com.
These are set at your domain registrar. A very common confusion: if your NS records point to provider A, then editing records at provider B has no effect. When DNS changes "don't work", check the NS records first to confirm you're editing in the right place.
SOA records
The SOA (Start of Authority) record holds administrative information about the DNS zone: the primary name server, a contact address for the zone, a serial number that changes when the zone is updated, and timers that control how secondary servers refresh. You rarely need to edit it yourself, but it's useful for troubleshooting.
CAA records
CAA records say which certificate authorities are allowed to issue SSL/TLS certificates for your domain.
example.com. CAA 0 issue "letsencrypt.org"
They're optional. If you add them, make sure they include every authority you actually use, or certificate renewals may fail. You can check a site's current certificate with the SSL Checker.
TTL: why changes take time
Every record has a TTL (time to live), measured in seconds. It tells resolvers how long they may cache the answer. A TTL of 3600 means one hour. After you change a record, some resolvers will keep serving the old answer until their cached copy expires.
Tip: if you're planning a change, such as moving to a new host, lower the TTL a day or so in advance. Once the change is done and stable, raise it again.
How to check your records
Enter a domain in the DomainBulleter to see its A, AAAA, CNAME, MX, TXT, NS, SOA and CAA records in one place, along with which provider appears to run its DNS. It's a quick way to confirm a change went through or to see how another domain is set up.
For related information:
- WHOIS Lookup shows the registrar, key dates and name servers registered for the domain.
- Who Is Hosting shows which company hosts a site and its network details.
A troubleshooting checklist
When "the DNS isn't working":
- Check the NS records. Are you editing at the right provider?
- Look up the record you changed. Does the checker show the new value?
- Consider the TTL. Has enough time passed?
- Look for conflicting records, such as a CNAME alongside other records on the same name.
- For email problems, check MX records and the TXT records for SPF, DKIM and DMARC.
DNS can feel intimidating, but most of the time you only deal with a few record types. Knowing what each one does makes setup and troubleshooting much less mysterious. Questions? Contact us.
Key takeaways
- A and AAAA records point a name to an IP address
- MX records route email
- TXT records hold verification and email authentication data
- CNAME records alias one name to another
- NS records decide which servers answer for your domain
Frequently asked questions
How long do DNS changes take to work?
It depends on the record's TTL. Changes can show up within minutes or take up to a day or more as caches expire.
Can I have a CNAME on my root domain?
Standard DNS doesn't allow a CNAME at the root alongside other records. Some providers offer alternatives such as ALIAS or flattening.
How do I check my domain's DNS records?
Use a free DNS checker to look up A, MX, TXT, CNAME and NS records for any domain.
What does TTL mean?
Time to live: how long resolvers may cache a record before asking for it again.
Why does my site work for some people but not others after a change?
Different resolvers may still have the old record cached until its TTL expires.
