You point your domain at a new server, refresh the page, and still see the old website. A colleague in another city already sees the new one. This is usually called DNS propagation, and it is less mysterious than it sounds.
What is really happening
DNS answers are cached. When a visitor's internet provider looks up your domain, it keeps the answer for as long as the record's TTL (time to live) allows. Until that time runs out, it keeps giving the old answer. Different providers looked up your domain at different moments, so they switch at different times.
How long it takes
- Changing a record such as an A or MX record: as long as the old TTL, often between a few minutes and a few hours.
- Changing nameservers: can take longer, up to a day or two, because the information is cached at a higher level.
Make planned changes faster
- A day before the change, lower the TTL of the records you will edit to 300 seconds (five minutes).
- Wait for the old TTL to expire, so everyone caches the short value.
- Make the change. Most visitors now switch within minutes.
- Once everything works, raise the TTL again.
Check what the world sees
Use our DNS checker to see the records your domain currently publishes. On your own computer, a browser or operating system cache can hold old answers too, so try a private window or another network before assuming something is wrong.
Keep both servers running
During a migration, keep the old server online until the new one has been serving traffic for a day or two. Visitors still on the old answer then see a working site instead of an error.
How IDX helps
DNS management is included with domains and hosting at IDX, and our migration team plans record changes and TTLs for you when you move a website to us.
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