Why do DNS changes take time to show up?
Devices and networks remember DNS answers for a set time, called the TTL, so they don't look them up on every visit. After a change, people keep seeing the old answer until their remembered copy expires. Record changes usually spread within minutes to hours; nameserver changes can take up to a day.
The short version
- Every DNS answer is remembered for a time set by its TTL.
- Until that time runs out, some visitors still get the old answer.
- Lower the TTL ahead of a planned change (at least one current TTL before), then raise it again afterward.
- Keep the old server running until everyone has moved over.
What is actually happening?
You change a record, your web company says it’s done, but half the office still sees the old site. Nothing is broken. You’re seeing DNS caching, which people often call propagation.
Each time someone visits, their device asks where your domain lives. To keep the web fast, that answer is cached by the device, the browser, sometimes the router, and the internet provider’s DNS servers. Cloudflare’s TTL page puts it simply: TTL controls how long each record is cached, and a longer TTL means updates take longer to go into effect.
A TTL of 3600 means one hour. A visitor whose copy was saved just before your change keeps the old answer for up to that long.
How long does it take?
It depends on the TTL that was in place before the change. Cloudflare lets you set TTLs from 60 seconds up to one day on standard records. Nameserver changes are slower because the registry’s records are cached too; Cloudflare tells new customers to allow up to 24 hours for a nameserver update.
Why does it matter?
During a website or email move, mixed answers mean some customers reach the new place and some reach the old one. If the old one has already been switched off, those visitors see an error, and some email can bounce.
How do I plan a smooth change?
- At least one TTL before (a day, for a one-day TTL): lower the TTL on the records you’ll change, for example to five minutes.
- Make the change, then keep the old server running until traffic has moved.
- Leave email records alone unless email is moving too. See how to change DNS without breaking email.
- Afterward: set the TTL back to a normal value.
What are the common mistakes?
- Shutting down the old host the same day. Visitors with cached answers land on nothing.
- Lowering the TTL at the same moment as the change. The old, long TTL is what visitors already have cached.
- Testing only on the office network, which may cache longer than others.
- Clearing your browser and assuming everyone else has too.
What if it still hasn’t shown up?
Try the site on mobile data, use a DNS lookup tool that checks from several locations, and open a private browser window. If a full day has passed and some people still can’t reach the site, check for a typo, a record added at the wrong DNS provider, or an SSL certificate not yet issued on the new host. Then see why is my website down.
How much does it cost, and how long does it take?
Nothing extra; TTL is a setting on each record. Planning adds a day’s notice before a move, which is what makes the switch quiet.
How does E-3 handle this?
When E-3 changes DNS for a site, we save the existing DNS records before changing them. If you’re moving a site to us, see can you move my website to your hosting.
Related questions
Common questions
- Why can I see the new site but my customer can't?
- Their device, browser or internet provider is still using a remembered copy of the old answer. It updates when that copy expires. Mobile data often shows the new version sooner.
- Can I speed it up?
- You can't make other networks forget. You can lower the TTL ahead of the change, at least as long before as the current TTL, so remembered copies expire faster.
- How do I know if it's propagation or a real problem?
- If a full day has passed and some people still can't reach the site, look for a typo, a record added at the wrong DNS provider, or a missing SSL certificate on the new host.
Rather talk it through?
Call our team, or send a note and we’ll reply within one business day. No pressure and no jargon.