What DNS is, what each record type does, and why changes sometimes take a while to take effect, without the jargon.
DNS stands for Domain Name System. Think of it as the internet's phonebook: it translates the domain name you type into a browser (like example.com) into the numerical IP address (like 93.184.216.34) that computers use to connect to each other.
Your domain's DNS settings are stored as individual "records." Each one tells the internet something different about your domain: where your website lives, where email should be delivered, which servers are authorised to send your email, and more.
Frequently asked questions
An A record maps your domain name to an IPv4 address. It is the most fundamental DNS record: it tells browsers which server to connect to when someone visits your website.
Example: example.com points to 93.184.216.34
You can have multiple A records for the same domain pointing to different IP addresses for load balancing or redundancy.
The same as an A record but for IPv6 addresses (the newer, longer format like 2001:db8::1). Most modern servers support both IPv4 and IPv6. If your domain has no AAAA records, your site is IPv4-only, which is not a problem today but increasingly relevant as IPv6 adoption grows.
A CNAME (Canonical Name) record creates an alias from one name to another. Rather than pointing directly to an IP address, a CNAME points to another domain name, which is then resolved to an IP.
Example: www.example.com points to example.com
CNAMEs are also widely used for third-party services, for example a CNAME to verify your domain with Google Search Console, or a DKIM CNAME for Microsoft 365.
MX (Mail Exchange) records tell other mail servers where to deliver email for your domain. They point to a mail server hostname and include a priority number: lower numbers have higher priority.
Example: 10 mail.example.com
If you use Google Workspace, your MX records point to Google's mail servers. If you use Microsoft 365, they point to Microsoft's. Having the wrong MX records is the most common cause of "I'm not receiving any emails" problems.
TXT records store arbitrary text. Originally intended for human-readable notes, they are now used for machine-readable data including:
NS (Nameserver) records identify the authoritative nameservers for your domain: the servers that hold your DNS records and answer queries about your domain. Your NS records are set at your domain registrar and typically point to your DNS provider (for example Cloudflare, AWS Route 53, or your web host).
Changing nameservers, such as when migrating to Cloudflare, transfers control of all DNS for your domain and can take up to 48 hours to propagate.
A PTR record is the reverse of an A record: it maps an IP address back to a domain name. PTR records are used for reverse DNS lookups and are important for email deliverability because many spam filters check whether the sending IP has a PTR record that matches the sending domain. Domain Checkup uses PTR records to identify your hosting provider.
When you update a DNS record, the change does not appear instantly everywhere. DNS resolvers around the world cache records for a period of time defined by the record's TTL (Time to Live) value. Until that cache expires, some users may still see the old record.
Propagation usually takes between a few minutes and 48 hours depending on the TTL. If you are planning a migration, lowering your TTL to 300 seconds (5 minutes) a day or two beforehand lets you make changes that spread quickly.
Your DNS provider is the company hosting your authoritative nameservers. Popular options include Cloudflare, AWS Route 53, GoDaddy, and Namecheap. Cloudflare's free plan is widely used because it offers fast global propagation, DDoS protection, and easy management. Your choice of DNS provider affects how quickly changes spread and how resilient your domain is to attacks.
Domain Checkup flags commonly expected DNS records that are absent, for example a missing SPF record when MX records are present, or no A record when a website is expected. Missing records do not always indicate a problem (some are intentionally absent), but they are worth investigating.
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