TTL: How Long DNS Changes Take to Spread
TTL stands for time to live, and it is the single setting that controls how long servers across the internet are allowed to remember a DNS record before checking for a fresh copy. It is the reason some changes appear within minutes and others seem to linger for a day.
Understanding TTL lets us plan changes so they happen quickly and with minimal disruption to your visitors and email.
What TTL Actually Controls
TTL is measured in seconds. A record with a TTL of 3600 may be cached for one hour; a record with 86400 may be cached for a whole day.
Lowering TTL Before a Change
The practical trick is to reduce the TTL well before a planned change, so caches expire quickly when the switch happens.
- A day or two ahead, lower the record's TTL to a few minutes.
- Wait for the old, longer TTL to expire everywhere.
- Make the actual change — it now spreads in minutes.
- Once stable, raise the TTL back up for efficiency.
Choosing Sensible Values
For records that rarely change, a longer TTL reduces lookups and improves resilience. For records you expect to move soon, a shorter TTL gives you agility. We balance the two based on your plans.
If you need a hand with any of this, your Progressive Robot delivery team is ready to help. Raise a ticket from the Support area of your client portal or speak to your account manager and we will guide you through the next steps.