What is DNS Propagation and How Long Does It Take?

DNS underpins everything your domain does, from loading your website to delivering your email. Understanding how it works - and why changes take time - will save you a lot of head-scratching when you move a site or switch hosting providers.

What is DNS?

The Domain Name System (DNS) is essentially the internet's address book. Every website and mail server on the internet has a numerical IP address, such as 100.21.242.3, but remembering strings of numbers for every site you visit would be impractical. DNS solves this by letting you use a memorable domain name and mapping it behind the scenes to the correct IP address.

When you type a domain into your browser, your computer queries DNS to find the IP address it needs, then connects to the server at that address. The whole process happens in milliseconds.

Common DNS record types

DNS zones are made up of individual records, each with a specific purpose. Here are the ones you are most likely to encounter.

• A record - Points your domain or subdomain to an IPv4 address. For example, yourdomain.com might point to 100.21.242.3. This is the most common record type.
• AAAA record - Works like an A record but points to an IPv6 address, such as 0000:0000:0000:0000:0000:ffff:6415:f203. Some browsers and networks prefer IPv6 when it is available.
• CNAME record - Points a subdomain to another domain name rather than an IP address. A typical use is pointing www.yourdomain.com to yourdomain.com, so both addresses load the same site.
• MX record - Tells the internet which mail server handles email for your domain. Without a correct MX record, incoming email will not reach you.

You can view and manage all of these in cPanel using the Zone Editor. If you need to point your domain's email to a different provider, the MX entry tool in cPanel handles that specifically.

What are nameservers?

If individual DNS records are entries in an address book, nameservers are the address book itself. They are the authoritative source for all DNS records belonging to your domain.

When you point your domain's nameservers to Kualo, all the DNS records we manage for you - A, AAAA, CNAME, MX, and others - are served from our nameservers automatically. This is usually the simplest way to connect a domain to your hosting, because you do not need to set up each record individually.

If you are not sure which nameservers to use, our article on which nameservers you should use covers shared hosting, reseller, and cloud or dedicated server accounts. Once you know the correct nameservers, you can update them at Kualo if your domain is registered with us.

What is DNS propagation?

When you change a DNS record or switch nameservers, that change does not take effect everywhere on the internet at once. DNS information is cached by servers and internet service providers around the world, and each cached copy has a time-to-live (TTL) value that controls how long it is kept before the server checks for an update.

Propagation is the process of those cached copies expiring and being replaced with the new information. Until a server's cache has refreshed, it may still direct visitors to your old hosting.

This is completely normal behaviour. It does not mean anything has gone wrong.

How long does propagation take?

Most DNS changes propagate within a few hours, but the process can take up to 48 hours in some cases. The exact time depends on:

• The TTL value set on the record before you changed it - a lower TTL means faster propagation.
• How frequently your internet service provider or resolver refreshes its cache.
• The record type and the DNS infrastructure of the networks involved.

Checking propagation progress

You can monitor how far your DNS changes have spread using these free tools:

• whatsmydns.net - shows results from DNS resolvers in dozens of countries at a glance.
• Google Admin Toolbox Dig - lets you query specific record types against Google's resolvers.

If most locations are returning the new values but a few are not, those remaining servers simply have not yet expired their cached copy. Give it a little more time.

Flushing your local DNS cache

Even after propagation is complete globally, your own computer may still be serving the old result from its local DNS cache. If your site looks correct when checked with the tools above but still shows the old version in your browser, flushing your local cache will fix it.

Our guide on how to clear your DNS cache walks you through the steps on both Windows and macOS. It is also worth clearing your browser cache at the same time, as browsers cache DNS responses independently.

Testing your site before DNS propagates

If you need to check that your site is working on our servers before you point your domain across, you can do this without making any DNS changes. Our guide on previewing your website with SkipDNS explains how, and using the hosts file is another option that gives you full browser-level testing.