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What is DNS propagation?
You changed a DNS record and some people see the new result while others still see the old one. That delay is DNS propagation.
What is happening
DNS is a distributed system. When someone looks up your domain, their resolver (at their ISP, or a public one like Cloudflare or Google) asks your authoritative name servers and then caches the answer for the length of the record's TTL (time to live). Until that cached copy expires, the resolver keeps serving the old value. "Propagation" is simply all of those caches expiring at different times.
How long does it take?
| Change | Typical time |
|---|---|
| Record edit with a short TTL (300s) | Minutes |
| Record edit with a 1-hour TTL | Up to an hour |
| Record edit with a 24-hour TTL | Up to a day |
| Changing name servers at the registrar | Hours, sometimes up to 48 hours |
How to check propagation
- Open the DNS checker.
- Enter your domain and the record type you changed (A, MX, TXT, and so on).
- Compare results from Cloudflare, Google and NextDNS. If they all show the new value, propagation has largely completed.
If the resolvers disagree, the ones showing old data have not expired their cache yet. You can also look at the TTL numbers: that is roughly the longest it can take.
How to make DNS changes smoother
- Lower the TTL (e.g. to 300 seconds) at least one old-TTL period before a planned change, then raise it again afterwards.
- Keep the old server running until propagation finishes.
- Flush your local cache:
ipconfig /flushdnson Windows,dscacheutil -flushcacheon Mac. - Remember browsers cache too; try a private window.
See also the DNS record types guide.
Frequently asked questions
Why do I still see the old website after changing DNS?
Your resolver, operating system or browser is still using a cached copy. Wait out the TTL or flush your caches.
Is DNS propagation really global?
Not literally. There is no push; it is just many independent caches expiring on their own schedules.
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