What TTL (time to live) means
A long TTL means fewer lookups but slower updates when you change something. Before a website migration, we lower the TTL so the switch takes effect quickly, then raise it again afterward. Most visitors see a change once their cached copy expires.
Why it matters for your website
TTL controls how quickly DNS changes spread, which matters when you switch hosts, move email or launch a new site. Planning it ahead can turn a long, messy cutover with downtime into a quick, smooth one.
Example
Before moving to a new host, a hypothetical marketing firm lowers its DNS TTL a day early, so when it changes the record, most visitors reach the new server quickly.
Tips
- Lower the TTL a day or two before any planned DNS change.
- Raise it back to a normal value once the change is stable.
- Write down current DNS settings before editing anything.
Common mistakes
- Lowering the TTL right when you make the change, which has little effect.
- Leaving TTL very low forever, adding unneeded DNS lookups.
Questions about TTL (time to live)
What is TTL (time to live)?
A DNS setting that tells other servers how long to remember a record before checking for changes.
What is a good TTL value?
Many records use an hour or more for everyday use. Shorter values are common just before and during a planned change.
Why is my DNS change not showing up yet?
Other servers may still be using the old record until its TTL runs out. Your own device and browser can cache it too, so try another network or clear your DNS cache.
