The Domain Name System (DNS) is the phonebook of the internet it translates human-readable domain names into the IP addresses computers use to connect. Every domain has a set of DNS records that control where traffic goes, who can send email on its behalf, and how mail servers discover each other. Use our free DNS Lookup Tool to query any record type in real time.
A Record (Address Record)
Maps a domain or subdomain to an IPv4 address. When someone types your domain into a browser, the A record tells it which server to connect to.
Example: example.com → 93.184.216.34
TTL (Time To Live) controls how long resolvers cache the record. Lower TTL (300–600 seconds) is useful when you are about to change servers; higher TTL (3600–86400) improves DNS resolution speed in stable setups.
AAAA Record
The IPv6 equivalent of the A record. If your hosting provider supports IPv6, you should have both A and AAAA records. IPv6 adoption is growing Google reports over 45% of traffic reaching Google via IPv6.
CNAME Record (Canonical Name)
Creates an alias from one domain name to another. Commonly used to point www.example.com to example.com.
Important constraint: A CNAME cannot coexist with other records at the same name. You cannot have a CNAME on a root domain (@) alongside an MX record use A records at the root and CNAMEs only on subdomains.
MX Record (Mail Exchanger)
Specifies which mail servers accept email for your domain. Each MX record has a priority value lower numbers are tried first. Check your MX records using our MX Record Checker.
TXT Record
Stores arbitrary text. Commonly used for:
- SPF authorises which servers can send email for your domain
- DMARC sets policy for handling unauthenticated email
- Domain verification Google Search Console, Apple, Microsoft 365 ownership proofs
Check your SPF and DMARC TXT records with the SPF Checker and DMARC Checker.
NS Record (Name Server)
Delegates authority over a domain to specific DNS servers. When you switch hosting, you change your NS records at your registrar to point to the new provider's nameservers. Propagation takes 24–48 hours in the worst case, though usually much less.
SOA Record (Start of Authority)
Metadata about the DNS zone itself primary nameserver, admin email address, and parameters controlling zone transfers and caching. Rarely changed manually; set automatically by your DNS provider.
PTR Record (Pointer Record)
Reverse DNS maps an IP address back to a domain name. Essential for mail server reputation. A mail server without a valid PTR record will be rejected by many receiving servers.
Frequently Asked Questions
How long does DNS propagation take?
Most DNS changes propagate within 1–4 hours, though some resolvers cache records for up to 48 hours depending on the previous TTL. Lower your TTL to 300 seconds before making planned changes to speed up propagation. The IANA root zone database is the authoritative source for TLD delegation.
What is the difference between a CNAME and an A record?
An A record maps a name directly to an IP address. A CNAME maps a name to another name, which is then resolved to an IP. CNAMEs add one extra lookup step but are easier to maintain when an IP address changes, since only the target record needs updating.
Can a domain have multiple A records?
Yes this is called DNS round-robin load balancing. Each DNS query returns all A records, and the client typically uses the first one. It is a simple form of load distribution but does not provide failover, since clients may cache a failed IP.