How long does it take for a domain change to work?

Most changes to a DNS record, like pointing your domain at a new website, start working within a few minutes and are seen almost everywhere within a few hours. Changing your nameservers takes longer, often several hours and occasionally up to two days. If nothing at all has changed after a full day, it is usually not a matter of waiting any more: something in the setup is wrong and worth checking.

Why there is a wait at all

When a phone looks up your domain, it does not ask your DNS company every single time. The answer gets remembered, or cached, in several places along the way: the phone itself, the browser, your home router, and your internet provider's servers. Each keeps the old answer until it expires, then asks again and gets the new one.

How long each one may remember is set by the record's TTL, short for time to live, a number of seconds shown next to each record in your DNS screen. A TTL of 3600 means "you may remember this for an hour". So right after a change, some people see the new site and some still see the old one, until all those remembered copies run out. People call this "propagation", though nothing is really spreading; old memories are just expiring.

Typical times for common changes

These are realistic ranges, not guarantees, and your provider may differ:

Editing an A or CNAME record (website): minutes for most people, up to the old TTL for the rest. Usually done within a few hours.
Adding a brand new record that did not exist before: often visible within minutes.
Changing MX records (email delivery): similar to website records, but mail sent during the switch can still land at the old mailbox for some hours.
Changing nameservers: a few hours is common, up to 48 hours in the worst case, because the information about which nameservers to use is itself remembered for a long time.
Security certificate on a new website: many providers issue it automatically once the records point at them, usually within an hour of the records working.
Transferring the domain to another registrar: around five to seven days, but this does not involve any DNS wait if your records do not change.
Renewing an expired domain: usually back within hours of paying, sometimes up to a day.

How to check what your customers really see

Your own computer is the worst place to test, because it is the one most likely to remember the old answer. Try these instead.

Your phone on mobile data

Turn Wi-Fi off, so the phone uses your cell carrier instead of your home internet, open a private browsing tab and type your domain. This is closest to what a new customer sees.

A private browser window

On your computer, a private or incognito window ignores the browser's cached pages. It still uses your computer's and router's memory, so it is a partial check.

Ask a public lookup service directly

On a Windows computer, open Command Prompt and type:

nslookup yourbusiness.com 8.8.8.8

This asks Google's public DNS service, bypassing your router and internet provider. The "Address" line in the answer should match the number your new website provider gave you. On a Mac, open Terminal and type "dig yourbusiness.com @8.8.8.8" for the same check. To check email, add "-type=mx" after nslookup on Windows.

There are also free websites that look up a domain from many countries at once and show a map of the answers. Search for "DNS propagation checker". They help you see whether the change has gone out widely.

Make the next change faster: lower the TTL first

If you know a change is coming, for example a new website going live on Thursday, you can shorten the wait:

A day or two before, edit the record you will change and set its TTL to the lowest your DNS screen allows, often 300 seconds (five minutes) or 600.
Wait for the old TTL to run out, so everyone has picked up the short one.
Make the real change. Now most visitors pick it up within minutes.
Afterwards, set the TTL back to the default or an hour.

When it is not propagation

If a full day has passed and you still see the old site, or nothing at all, waiting will not help. Check these instead:

You edited the wrong DNS. Your records live wherever your nameservers point, which is not always where you bought the domain. Nameservers vs DNS records shows how to find the right place.
An old record is still there. Two A records for the same name, or a leftover AAAA record, can send some visitors to the old host forever.
A forwarding rule at the registrar overrides your records.
A typo in the number or name. Copy and paste values instead of retyping them.
The domain is on hold or expired, which no record change can fix.
The new site is not set up to answer for your domain yet. Many providers need you to add the domain on their side as well as change the records.

Email during the switch

When you change where email is delivered, mail can trickle into the old mailbox for a while after the change. Keep the old mailbox open and check it daily for at least a week. Change where mail is delivered before you cancel the old service, never after. When the website is what you are changing, leave the email records alone, as connecting your domain to a new website explains, and email does not wait for anything.

A launch-day routine

Lower the TTL a day ahead.
Make the change in the morning, early in the week.
Check on your phone with Wi-Fi off after fifteen minutes, then after an hour.
Run the nslookup check against 8.8.8.8.
Send a test email to your business address and reply to it.
If nothing has changed after a day, go through the list of real problems above.

For the rest of the day itself, the website launch day checklist covers forms, phone links and Google. And if you are still looking for the new site to point at, you can see your site rebuilt first and switch only once it is ready.