Guide
Website not loading after a DNS change: how to fix it
After a DNS change, a site can look broken for a few hours because different networks keep the old answer cached until its time to live runs out. Check the records at your DNS provider, look them up from outside your own network, flush your local cache and confirm the new host has the site ready. Most problems clear within hours, though some take up to a day or two.
How it works
What happens when someone types your domain
- Browser asksIt checks its own cache first
- Your network resolverChecks its cache, then asks upwards
- Nameservers answerThey hold the records you set
- Browser connectsTo the server at the address it was given
- Server respondsIt must have your site and certificate ready
Why it is slow
Propagation and TTL, plainly explained
DNS is the internet address book that turns a name like example.co.uk into a server address. If you want the basics, see our guide on what DNS is. When you change a record, there is no single switch that updates the whole world. Instead, thousands of resolvers run by internet providers and companies keep copies of earlier answers, and each copy expires on its own timer.
That timer is the TTL, or time to live, measured in seconds. A TTL of 3600 lets resolvers keep an answer for an hour, and 86400 allows a full day. If your old record had a long TTL, some visitors will keep reaching the old server until it runs out. This is why people say DNS changes can take up to 48 hours. In practice, most changes show within an hour or two, but the longer allowance is a safe planning guide.
The term propagation is a little misleading. Nothing is being pushed around. Caches simply expire at different times, so two people in different places can see different results for the same domain during the changeover.
Symptoms
What you see and what it usually means
| Symptom | Probable cause | What to do |
|---|---|---|
| Old site still shows for some people | Cached records not yet expired | Wait for the TTL, flush local cache |
| Site not found or cannot be reached | Records missing, wrong or nameserver typo | Check records at the DNS provider |
| Default hosting page appears | Domain reaches the server but is not set up for it | Add the domain in the control panel |
| Certificate warning | Certificate not issued yet for the new server | Allow time, then recheck. See the SSL guide |
| Site loads with www only | Missing record for the bare domain, or the other way | Add both records and a redirect |
| Email stopped working | MX records changed or removed | Restore the correct MX records |
| Works for you, not for others | Your hosts file or local cache differs | Check from another network |
Moving to us and want it smooth?
Free migration on Small and higher plans billed yearly, so the new site is ready before DNS changes.
Step by step
Diagnosing the problem
Confirm what you changed
Was it nameservers, or an A record, or both? Changing nameservers moves control of every record to a new provider, so all records must be recreated there.
Check the records at the source
Log in to wherever the DNS is hosted and read the current A, CNAME and MX records. Check for typos in numbers and names.
Look up from outside
Use an online DNS lookup tool to query your domain. These query public resolvers, so they show what the wider internet sees, not just your own cache.
Compare with the expected address
The A record should show the IP address of the server that holds your site. If it shows the old address, the change has not reached that resolver yet.
Flush your own caches
Clear the operating system DNS cache and restart the browser. Try mobile data to bypass your home network cache.
Test that the new host is ready
The domain must be added to the hosting account, the site files uploaded and the certificate issued. DNS can be perfect and the site still blank.
Flushing
Clearing your own DNS cache
Your own computer remembers DNS answers too. On Windows, open Command Prompt and run ipconfig /flushdns. On a Mac, the command differs by version, and restarting the computer is the simplest universal alternative. On phones, switching flight mode on and off, or changing between wifi and mobile data, usually clears the cache.
Browsers keep their own cache as well. Closing every window and reopening, or using a private window, often helps. If you still see the old site, check your hosts file, a local text file that can force a domain to a fixed address. People add entries there while testing a migration, then forget them. If your own computer shows a different result from everyone else, this is a prime suspect.
Narrowing down
A DNS problem or a hosting problem
Points to DNS
- A lookup tool shows the wrong or no address
- Results differ between networks and places
- The domain is not found at all
- The nameservers differ from what you set
- The change was made very recently
Points to the hosting side
- Lookups show the right address everywhere
- You reach the server but see a default page
- There is a certificate or 403 or 500 error
- The domain is not added to the account
- The files are missing from the right folder
Numbers
Timings to keep in mind
Doing it right
How to plan a DNS change to avoid downtime
The best fix is prevention. A day or two before the change, lower the TTL on the records you will change to something short, such as 300 seconds. Then when you switch, caches expire within minutes. Once everything works, raise the TTL again to reduce lookups.
Get the new site fully working before you point the domain. Upload files, import the database, set up email and check the site using a preview or a hosts file entry on your own computer. Then change DNS. Leave the old hosting running for at least a few days, so anyone still reaching the old address sees a working site, and copy any new orders or form entries across afterwards. Our website migration checklist sets out the full order of work.
Remember email. If you change nameservers, you must recreate the MX records at the new provider, or mail will stop arriving. Check those first. See how to point a domain to hosting for the records to use.
Checklist
After a DNS change, check these
- The A record shows the new server address
- www and the bare domain both resolve
- MX records are present for email
- The domain is added in the hosting control panel
- Files and database are in the right place
- The certificate has been issued
- Your local cache and hosts file are clear
- You have tested from mobile data
Common slips
Mistakes that cause long outages
Changing nameservers without copying records
The new provider starts empty, so mail and subdomains vanish.
Typing the wrong IP address
One wrong digit sends visitors to an unrelated server.
Ignoring a long TTL
A day-long cache delays every change.
Pointing before the site is ready
Visitors see an empty or default page.
Forgetting MX records
Email silently stops arriving.
Editing the wrong DNS zone
If nameservers are elsewhere, changes at the registrar do nothing.
FAQ
Common questions
How long does a DNS change take?
Often an hour or two, but allow up to 48 hours because cached answers expire at different times.
Can I speed up propagation?
Not directly. Lowering the TTL before the change is the best way, and you can flush your own cache to see the update sooner.
Why does the site work for me but not my customer?
Your device and their network cache different answers, or you have a hosts file entry. Compare using a public lookup tool.
Will my email be affected?
It can be if MX records change or disappear. Check them straight after any DNS or nameserver change.
Should I keep my old hosting running?
Yes, for a few days, so visitors with cached records still reach a working site.
Keep reading
Related pages
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