What is DNS TTL (time to live)?

DNS TTL, or time to live, is a number of seconds attached to a DNS record. It tells resolvers how long they may keep the answer before asking again.

Why do DNS changes seem slow?

When you change a record, resolvers around the world keep serving the old answer until their cached copy expires. That is what people call propagation. A record with a TTL of 3600 can be served from cache for up to an hour after you change it.

What TTL should I use?

Common values run from a few minutes to a day. A short TTL such as 300 seconds helps when you plan to move a site or switch a provider, because the change reaches visitors quickly. A longer TTL reduces lookups for records that rarely change.

How does this relate to expired domains and certificates?

After a domain lapses and is renewed, or after a validation record changes, cached answers can delay recovery for some visitors. Lowering the TTL before a planned change is a cheap precaution.

Where Datumboard fits

Datumboard puts the signals behind this in one dashboard for your client sites and side projects. It is in early access, and you can join the list below.