DNS propagation is the time it takes for a change to your domain's DNS records, such as a new IP address or new nameservers, to be seen by every DNS resolver on the internet. Most record changes show up within a few minutes to a few hours. A nameserver change can take up to 24 to 48 hours, because resolvers keep old answers in their cache until the time-to-live (TTL) runs out.
DNS propagation in one paragraph
When you edit a DNS record, the change is live on your nameserver straight away. Nothing is pushed around the world. Resolvers run by internet providers, mobile networks and public services keep a cached copy of the old answer until its TTL expires. Propagation is the window while those caches expire at different times.
How DNS propagation works, step by step
To see why changes are not instant, it helps to follow one lookup from a visitor's phone to your website. The domain name system works like a chain of address books, and several of them keep short-term copies.
- The browser and device check their own cache. If you visited the site recently, your phone or laptop may already have the answer stored.
- The request goes to a recursive resolver. This is usually run by your internet or mobile provider, or by a public service you chose. If it has a cached answer that has not expired, it uses that.
- If not, the resolver asks the root and the registry. For a .co.za name, it is directed to the .co.za registry servers, which reply with the nameservers listed for your domain.
- The resolver asks your authoritative nameserver. This server holds your real DNS zone: A, AAAA, MX, CNAME, TXT and other records.
- The answer is cached and returned. The resolver stores the answer for as long as the TTL says, then hands it to the device, which may cache it too.
Steps 1, 2 and 5 are where propagation delays come from. Your change exists at step 4 immediately, but a resolver that cached the old answer at step 5 will keep serving it until the TTL expires. Our guide on how DNS works for .co.za domains covers the registry side of this chain in more detail.
What affects DNS propagation time?
Three things decide how long the old answer hangs around. Once you know which one applies to your change, you can usually predict the wait quite well.
| Factor | What it means | Effect on the wait |
|---|---|---|
| TTL on the record | The number of seconds a resolver may cache the answer, set by whoever manages the DNS zone | A TTL of 300 means about five minutes. A TTL of 86400 means up to 24 hours. |
| Type of change | Editing a single record inside your zone versus changing the domain's nameservers at the registry | Nameserver changes rely on the registry's own TTL, so they usually take longest. |
| Resolver behaviour | Some providers keep answers longer than the TTL or refresh on their own schedule | A few visitors may see old results for a while after everyone else. |
| Local caches | Browser, operating system and router caches on the visitor's side | Can make one device look "stuck" even when the resolver has the new answer. |
| Negative caching | If someone looked up a record before it existed, the "does not exist" answer is cached too | A brand new subdomain can take a little longer to appear for some users. |
How long does DNS propagation take?
There is no single number, but these are realistic ranges for the changes small businesses make most often. They assume normal TTL values of between a few minutes and a day.
| Change you make | Typical time to be visible for most people | Example |
|---|---|---|
| A or AAAA record (website IP address) | Minutes to a few hours, depending on the old TTL | Pointing your site to a new hosting server |
| MX record (where email is delivered) | Minutes to a few hours | Moving business email to a new provider |
| CNAME or TXT record | Minutes to a few hours | Verifying a domain with Google or adding SPF |
| New record that never existed | Often within minutes | Adding shop.yourbusiness.co.za |
| Nameserver change | A few hours, sometimes up to 24 to 48 hours | Moving DNS management to a new host or registrar |
The figure of "up to 72 hours" that you see quoted is a cautious upper limit from the days when long TTLs were normal. Today most changes are visible to the large majority of people within a few hours, but it is still sensible to plan important moves with a day of margin.
Examples of DNS propagation in everyday hosting
You will meet propagation whenever a website, email or domain moves. These are the situations our support team sees most often:
- Moving to a new host. You copy the website, then update the A record or the nameservers. For a while, some visitors reach the old server and some the new one. Our step-by-step guide to migrating your website to a new host explains how to keep both copies in step during that window.
- Registering a new domain. When you register a domain with our domain name registration, it is set to our nameservers. The domain usually starts resolving within a few hours of the registry accepting it.
- Transferring a domain. A registrar transfer does not have to change DNS at all. If the nameservers stay the same, your website and email keep working during a domain transfer. Problems only start if the nameservers are switched to a zone that is missing records.
- Switching email providers. After changing MX records, some messages may still arrive at the old mailbox for a few hours. Keep the old mailbox open until mail stops arriving there.
- Adding SSL. A free SSL certificate cannot be issued until the domain points to the server that requests it, so certificates sometimes fail on the first try straight after a move.
Need a domain with DNS you can manage yourself?
Our .co.za domains cost R109 a year to register and renew, with nameserver management, free domain privacy, domain lock and auto-renewal included. Manage records yourself or ask our team to set them up for you.
How to check DNS propagation
You do not have to guess whether a change has spread. These checks show you what different resolvers are returning right now.
- Use an online DNS propagation checker. Search for a "DNS propagation checker" and enter your domain and the record type. It queries resolvers in many countries and shows which ones return the new value.
- Ask your authoritative nameserver directly. On a computer, run
dig yourdomain.co.za A @ns1.yourprovider.com(ornslookup yourdomain.co.za ns1.yourprovider.comon Windows). If this shows the new value, your change is saved correctly and you are only waiting on caches. - Compare public resolvers. Run the same lookup against 8.8.8.8 (Google) and 1.1.1.1 (Cloudflare). If they differ, propagation is still in progress.
- Check the TTL that is left. The
digoutput shows the remaining TTL in seconds next to each answer. That number tells you roughly how long that resolver will keep the old value. - Test from a mobile network. Switching your phone from Wi-Fi to mobile data uses a different resolver, which is a quick real-world check.
If the authoritative nameserver itself still shows the old value, the problem is not propagation. The record was not saved, was saved in the wrong zone, or the domain is using different nameservers from the ones you edited. Our explainer on what an NS record is helps you confirm which nameservers are really in charge.
How to speed up DNS propagation
You cannot force every resolver in the world to drop its cache, but you can make the wait much shorter with a little planning.
- Lower the TTL a day before. Set the records you plan to change to a TTL of 300 seconds at least one full old-TTL period in advance. When you make the real change, caches will expire within minutes.
- Change records rather than nameservers where possible. Updating an A or MX record is usually quicker than switching nameservers, because you control the TTL.
- Copy the whole zone first. Before you change nameservers, recreate every record (website, mail, SPF, DKIM and verification records) on the new DNS host so nothing breaks while caches catch up.
- Flush your own caches. Clear your browser cache, restart the browser and flush the operating system DNS cache (for example
ipconfig /flushdnson Windows) so your own device is not the thing holding the old answer. - Raise the TTL again afterwards. Once everything works, set the TTL back to a normal value such as 3600 seconds to reduce lookups.
DNS propagation mistakes that cause downtime
Most "propagation problems" that reach our support desk are actually configuration problems. Watch for these:
- Cancelling the old hosting too early. Keep the old server running until propagation is complete, usually two days, so visitors on old caches still see a working site.
- Forgetting email records. Moving nameservers without copying MX, SPF and DKIM records is the most common cause of missing email after a move.
- Editing DNS at the wrong place. If your domain uses your host's nameservers, changes made at the registrar's DNS editor will have no effect, and the other way round.
- Typing the wrong IP address. A wrong A record will propagate just as faithfully as a correct one. Double-check the value before you save.
- Letting the domain expire. An expired domain stops resolving no matter how the records are set. Turn on auto-renewal for your important domains.
DNS propagation is a normal part of how the internet stays fast and reliable, not a fault. Plan your changes with a low TTL, check the authoritative answer first, and allow a day of margin for nameserver moves. If you would rather not handle the records yourself, our team can set up the DNS for your domain, website and email so the change is done once and done right.
