What is a DNS record?
What DNS does, the record types that matter (A, AAAA, CNAME, MX, TXT, NS, TTL), and the three ways DNS affects SEO: reachability, speed, and migration propagation.
A DNS record is an instruction stored in the Domain Name System that tells the internet where to find the services behind your domain — which server answers for your website, where your email goes, and more. DNS is the internet’s address book: it translates a human-friendly name like example.com into the numeric IP address a computer actually connects to. Get the records wrong and nothing else works, because visitors and search engines can no longer find your site.
What DNS actually does
When someone types your domain, their device asks a chain of DNS servers “what is the address for this name?” A resolver works its way up to the authoritative nameservers that hold your records and returns the answer, which the browser then uses to connect. All of this happens in the milliseconds before your server is even contacted — it is the very first step of loading any page.
The record types that matter
A domain has several kinds of record, each answering a different question. A maps the domain to an IPv4 address; AAAA does the same for IPv6. CNAME makes one name an alias of another (commonly www pointing at the root domain). MX directs email to the right mail servers. TXT holds arbitrary text used for verification and email security — this is where a Search Console verification string, and SPF, DKIM, and DMARC email records, live. NS names the authoritative nameservers for the domain. Each record also has a TTL (time to live) that controls how long it is cached before being looked up again.
Why DNS matters for SEO
Three ways. Reachability: if the A record is wrong or the nameservers are down, Googlebot gets nothing and pages fall out of the index. Speed: the DNS lookup is the first contributor to time to first byte, so a slow or distant DNS provider slows every first visit. Migrations: when you change hosts, DNS changes have to propagate, and a long TTL means the old address lingers in caches — some visitors and crawlers hit the old server for hours after you cut over.
Common DNS problems
The usual culprits are a stale A record still pointing at an old host after a migration, a missing AAAA record on a network that expects IPv6, a CNAME placed at the apex (root) domain where it is not allowed, a TTL set so high that changes take a day to take effect, and outright nameserver downtime, which makes the entire site unreachable regardless of how healthy the server is.
How to check yours
Our DNS lookup checker reads your domain’s A, AAAA, MX, TXT, and NS records so you can confirm they point where you expect — the fastest way to rule DNS in or out when a site is unreachable or a verification is failing. To see how long the domain has been established while you are looking at its records, the domain age checker reports its registration history.
Frequently asked questions
- What is a DNS record?
- A DNS record is an instruction in the Domain Name System that tells the internet where to find the services behind your domain — which server hosts your website, where email is delivered, and so on. DNS acts as the internet's address book, translating a domain name into the numeric IP address computers use to connect.
- What are the main types of DNS record?
- The most common are A (maps the domain to an IPv4 address), AAAA (to an IPv6 address), CNAME (makes one name an alias of another), MX (directs email), TXT (holds verification and email-security data like SPF and DKIM), and NS (names the authoritative nameservers). Each has a TTL controlling how long it is cached.
- Does DNS affect SEO?
- DNS is not a ranking factor, but it is critical infrastructure. If DNS is misconfigured or the nameservers are down, Google can't reach your site to crawl it and pages drop from the index. A slow DNS provider also adds latency to the start of every page load, since the lookup is the first step of connecting.
- What is a TXT record used for?
- A TXT record stores arbitrary text at your domain, most often for verification and email security. Google Search Console can verify domain ownership with a TXT record, and email authentication standards SPF, DKIM, and DMARC are published as TXT records to help prevent spoofing of your domain.
- Why does my site go down after a DNS change?
- DNS changes have to propagate, and records are cached according to their TTL (time to live). If the TTL was set high, resolvers keep returning the old address for hours after you update it, so some visitors and crawlers still reach the old server. Lowering the TTL before a migration reduces this window.
- How do I check my DNS records?
- Use a DNS lookup tool to query your domain's A, AAAA, MX, TXT, and NS records and confirm they point where you expect. This is the quickest way to diagnose an unreachable site, a failing Search Console verification, or email delivery problems, all of which trace back to a misconfigured record.