The number that controls propagation.
WHAT IT IS
Time to live, in seconds. How long a resolver may keep an answer before asking again.
TYPICAL VALUES
14400 seconds is four hours, a common default. 3600 is one hour. 300 is five minutes. 86400 is a day.
THE TRADE
A long TTL means less query traffic and slower changes. A short TTL means faster changes and slightly more query traffic.
For a small site, the query traffic is irrelevant. The change speed is what matters.
BEFORE A PLANNED CHANGE
Lower the TTL to 300, at least a day in advance.
Then, when you make the change, it propagates within minutes rather than hours.
Raise it afterwards.
That single practice is what separates a smooth migration from a confusing one.
WHERE TO SET IT
On each record, in whichever system holds your DNS.
At Cloudflare, proxied records manage TTL automatically and the setting is unavailable.
THE MISTAKE
Changing nameservers or records with a long TTL still set, then wondering why some visitors see the old site for a day.
