Free tool
Has your DNS change spread?
After changing a DNS record, resolvers around the world keep the old answer until its time-to-live (TTL) runs out. We ask resolvers on several continents at once.
Why it takes time
A resolver (your internet provider's, Google's, Cloudflare's) remembers each answer for as long as its TTL allows. As long as that time has not run out, it keeps giving the old value, even if you changed it.
01
Plan ahead
A day before a move, lower the TTL to 300 seconds (5 minutes).
02
Make the change
Resolvers pick up the new value within 5 minutes.
03
Raise it back
Once everything works, go back to 1 hour or more.
Questions
“48 hours of propagation”: true?
Only if the TTL is 48 hours. In practice, most changes are visible within an hour.
My computer still sees the old site
Your computer and browser have their own memory. Restarting the browser, or waiting a few minutes, is usually enough.
Frequently asked questions
Has my DNS change propagated?
Enter your domain: the tool asks about a dozen public resolvers on several continents the same question and compares their answers with the one from the authoritative server. You see which ones already show the new value.
Why does DNS propagation take time?
A resolver keeps each answer as long as its TTL allows. Until that delay runs out, it keeps returning the old value, even if you have changed it.
Does propagation really take 48 hours?
Only if the TTL is 48 hours. Going forward, lower it to 300 seconds the day before a move, then raise it back to 1 hour or more once everything is in place.
My computer still shows the old site. What can I do?
Your computer and your browser have their own memory. Restarting the browser, or waiting a few minutes, is usually enough.
