TTL stands for Time To Live. It is a value set on each DNS record that tells resolvers how long, in seconds, they may cache the answer before checking again. TTL directly controls how fast your changes propagate.
How TTL Works
When a resolver looks up a record, it stores the result for the length of the TTL. During that window it returns the cached answer without re-querying. Once the TTL expires, it fetches a fresh copy.
| TTL value | Caching duration | | --------- | ---------------- | | 300 | 5 minutes | | 3600 | 1 hour | | 14400 | 4 hours | | 86400 | 24 hours |
Choosing the Right TTL
- Low TTL (300 to 600): changes apply quickly, but resolvers query more often. Useful right before a planned change.
- High TTL (14400 to 86400): fewer queries and slightly better performance, but changes take longer to spread.
Practical Strategy
- A day before a major change, lower the TTL on the affected record, for example to 300.
- Wait for the old, longer TTL to expire so caches refresh to the short value.
- Make your change. It now propagates within minutes.
- After confirming everything works, raise the TTL back to a normal value.
This approach minimises downtime during migrations. For records that rarely change, a higher TTL is fine and reduces unnecessary lookups. You set TTL per record in the cPanel Zone Editor.