Oct
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DNS Records Explained: A, CNAME, MX, TXT, and What They Do

10/06/2026 12:00 AM oleh Seovaro Team dalam


DNS Records Explained: A, CNAME, MX, TXT, and What They Do

DNS is the internet's phonebook, and like a phonebook, nobody thinks about it until something goes wrong. Then it becomes the only thing that matters — because when DNS breaks, your website doesn't load slowly or look broken. It simply doesn't exist, as far as the entire internet is concerned.

Every website owner eventually has to touch DNS: pointing a domain at a new host, setting up email, verifying domain ownership, adding a CDN. The vocabulary is small — a handful of record types — but the stakes are high, because one wrong record can take down your site, your email, or both. Let's make sure that doesn't happen.

What DNS Actually Does

When someone types your domain into a browser, the browser doesn't know where your website lives. It asks the Domain Name System: "what's the IP address for this name?" DNS answers with the right server address, the browser connects, and your site loads. The whole exchange usually takes milliseconds.

That answer comes from DNS records — entries in your domain's DNS zone that map names to values. Different record types handle different jobs: one points your domain at a server, another routes your email, another proves you own the domain. You manage them wherever your nameservers live — your registrar, your host, or Cloudflare.

Two concepts before we dive in: propagation — DNS changes aren't instant worldwide; servers cache the old value until its TTL expires, so full propagation takes minutes to hours (occasionally 48). And TTL (time to live) — how long a record is cached. Before a planned migration, lower TTLs to 300 seconds a day ahead; it makes the cutover dramatically smoother. Our guide on how to migrate your website to a new host without losing SEO covers this timing trick in detail.

A Records: Your Domain's Street Address

The A record (Address) is the most fundamental DNS record: it maps your domain name directly to an IPv4 address.

```

yoursite.com. A 192.0.2.44

```

That's it — "yoursite.com lives at 192.0.2.44." When you point a domain at a web host, you're usually creating or editing an A record. The AAAA record is the IPv6 equivalent, mapping to the longer IPv6 address format.

To see what your domain currently resolves to, run a domain into IP lookup — it shows the exact IP address your domain points at right now. After any hosting change, this is how you confirm the new A record is live (remembering that your view may update before the rest of the world's, thanks to propagation).

CNAME Records: Aliases

A CNAME (Canonical Name) record points one name at another name, rather than at an IP address:

```

www.yoursite.com. CNAME yoursite.com.

```

"www.yoursite.com is just an alias for yoursite.com — go look up that name's A record." CNAMEs are how www subdomains, CDN endpoints, and hosted services (email providers, site builders) attach to your domain without you managing their IPs.

The one hard rule: a CNAME can't be used at the apex (the bare domain) and can't coexist with other records on the same name. Standard setup: A record on the apex, CNAME on www. Some providers offer "CNAME flattening" that works around the apex limitation — Cloudflare does this automatically.

MX Records: Email Routing

MX (Mail Exchange) records tell the internet where to deliver email for your domain:

```

yoursite.com. MX 10 mail.yoursite.com.

```

The number is priority — lower numbers are tried first. If you use Google Workspace or Microsoft 365 for email, your MX records point at their servers, and getting them wrong means silently losing email (the worst kind of DNS failure, because nothing visibly breaks — messages just vanish).

This is also why DNS mistakes are so dangerous during migrations: people remember to move the website's A record and forget the MX records, and email stops working with no error message anywhere. Before touching DNS, document your existing records. After any change, verify with a find DNS records lookup that your MX records survived intact.

TXT Records: Verification and Policy

TXT records hold arbitrary text: domain ownership verification (Search Console, SaaS products), SPF (which servers may send your email), DKIM (cryptographic email signatures), and DMARC (what to do with mail failing the first two). Email deliverability lives and dies on these three — if newsletters land in spam, misconfigured SPF/DKIM/DMARC is the first suspect.

NS Records: Who's in Charge

NS (Name Server) records declare which servers are authoritative for your domain — where the world should ask for all the records above. When you "point your domain to Cloudflare," you're changing NS records at your registrar.

This matters for one practical reason: you must know where your DNS is actually managed. People routinely edit DNS at their registrar while their NS records point to Cloudflare — then wonder why nothing changes. Before editing anything, confirm where your nameservers point. A domain hosting checker can help untangle where your domain's services actually live.

Common DNS Disasters (And How to Avoid Them)

  • Deleting MX records during a migration. Document all records before changing nameservers; verify email records after.
  • High TTL before a move. A 24-hour TTL means a mistake takes a full day to fix globally. Lower TTLs to 300 well before planned changes.
  • Editing DNS in the wrong place. Confirm your authoritative nameservers first, then edit there.
  • CNAME at the apex. It violates the spec and breaks intermittently. Use A/AAAA records (or your provider's flattening) for the bare domain.
  • Forgetting the www. Configure both apex and www, with a redirect between them.
  • Typos in IP addresses. One wrong digit = total outage. Verify every change with a DNS lookup.

How to Inspect Any Domain's DNS

You don't need registrar access to see a domain's public DNS — it's all queryable. A find DNS records tool shows a domain's A, MX, TXT, NS, and other records instantly. Use it to snapshot records before a migration, debug email issues (missing SPF/DKIM/DMARC is the first suspect when mail lands in spam), research competitors' infrastructure, or verify that new values have propagated.

The Bottom Line

DNS is five record types you'll actually touch: A (where the site lives), CNAME (aliases), MX (email routing), TXT (verification and email policy), and NS (who's in charge). Document your records before changing anything, lower TTLs before migrations, verify every change with a lookup — and respect the phonebook.

Look up any domain's DNS records free with our Find DNS Records tool — see A, MX, TXT, NS and more in one click.

FAQ

How long does DNS propagation take?

Usually minutes to a few hours; up to 48 hours in rare cases. The record's TTL controls how long servers cache the old value. Lower your TTL to 300 seconds a day before planned changes to make propagation fast, then raise it afterward.

What's the difference between A and CNAME records?

An A record maps a name directly to an IP address ("yoursite.com → 192.0.2.44"). A CNAME maps a name to another name ("www.yoursite.com → yoursite.com"). Use A records for the apex domain and CNAMEs for subdomains and aliases. A CNAME can't be used at the apex in standard DNS.

Will changing DNS affect my SEO?

The DNS change itself doesn't affect rankings — but downtime does. If DNS is misconfigured and your site is unreachable, Google can't crawl it, and prolonged outages cause deindexing. Plan migrations with low TTLs, verify records immediately, and monitor closely for 48 hours.

Why is my email not working after changing nameservers?

Almost certainly the MX records (and possibly SPF/DKIM/DMARC TXT records) weren't recreated at the new DNS provider. Email routing is entirely DNS-driven — the website can work perfectly while email silently fails. Always migrate mail records alongside web records.

Can I see someone else's DNS records?

Yes — DNS is public by design. Any domain's A, MX, TXT, NS, and other records are queryable by anyone. This is normal and expected; it's how the internet routes traffic and email. Only the registrar account itself (which controls the records) is private.