DNS records are the internet’s address book. They tell browsers where a website lives, where email goes, and which services a domain uses. When a site or email stops working, checking DNS records is usually the first diagnostic step. This guide shows you how.
The records you will meet
- A: maps a domain to an IPv4 address, such as 93.184.216.34.
- AAAA: the same job for IPv6 addresses.
- CNAME: points one name at another name, often used for subdomains.
- MX: names the mail servers that accept email for the domain, with a priority number.
- TXT: holds text, used for verification and email security policies like SPF and DKIM.
- NS: names the servers that hold the domain’s DNS records.
- SOA: holds admin details about the DNS zone itself.
Step-by-step: check a domain’s records
- Enter the domain name, without any page path. Use the root domain for most checks, or the full subdomain when that is what you are testing.
- Check the A or AAAA record first. If it points to the wrong server, the website will load the wrong content or nothing at all.
- Check the MX records if email is the problem. A missing or wrong MX record means mail goes nowhere.
- Check TXT records for email authentication. A missing SPF record is a common reason mail lands in spam.
- Check NS records if nothing resolves at all. Wrong name servers mean the whole zone is unreachable.
- Compare what you see with what your host or registrar says it should be. Any mismatch is your lead.
Why changes take time to appear
DNS results are cached all over the world, and each record carries a TTL, a time-to-live in seconds. Until the TTL expires, resolvers keep showing the old value. That is why a DNS change can look instant to one person and broken to another for hours. Before making a change, lower the TTL a day ahead so the switch spreads faster.
Common mistakes
Checking the wrong name is the classic error: www.example.com and example.com can have different records. Another is reading a cached result and concluding the change failed. A third is editing records at the wrong provider: if your name servers point elsewhere, edits at your registrar do nothing.
Try it the faster way
Enter any domain in the tool below to check its DNS records instantly.
Prefer the full page? Open the DNS record checker directly.
Quick tips
- Always check both the root domain and the www subdomain.
- Note the TTL before changing anything, so you know how long propagation takes.
- Take a screenshot of working records before editing, as your rollback reference.
DNS looks mysterious until you learn the record types. After that, most website and email problems narrow down to one wrong line, and you will know exactly which line to check.
Frequently asked questions
How long do DNS changes take to spread? It depends on the TTL of the old record, which can range from minutes to 48 hours. Lower the TTL to a few minutes a day before a planned change, and the switch will spread much faster. Some resolvers ignore low TTLs, so allow extra time for stragglers.
Why does a site work for me but not for someone else? Usually caching: your resolver has the new record and theirs still holds the old one. Different networks also use different resolvers with different caches. Waiting out the TTL, or switching to a public resolver, usually resolves the discrepancy.
What is the difference between an A record and a CNAME? An A record points a name directly at an IP address, while a CNAME points a name at another name. Use A records for the main address and CNAMEs for aliases like subdomains, so changing the address in one place updates all aliases.