What is a TTL in DNS and what should I set it to?
What TTL actually does
Every DNS record has a TTL value, measured in seconds. It tells recursive resolvers — the servers your visitors' devices ask for DNS answers — how long they may keep that answer before asking your authoritative nameserver again.
A longer TTL means fewer DNS lookups and slightly faster responses for repeat visitors. A shorter TTL means changes propagate faster, but your nameservers get more queries.
TTL does not control how fast your own DNS provider publishes a change. It controls how long the old answer can linger in caches elsewhere on the internet.
Choosing a value
For stable records that rarely change, 3600 seconds is a sensible default. Many providers default to 3600 or 14400 (4 hours).
If you are about to migrate hosting, change email providers, or move nameservers, lower the TTL to 300 seconds at least a day before the change. After the change is verified, raise it back.
Some providers enforce minimums, often 300 seconds, and some CDNs or proxied records override your TTL entirely.
- Stable website A record: 3600 seconds
- Before a migration: 300 seconds
- MX records: 3600 seconds is typical
- TXT records for verification: 300–3600 seconds
- After migration: raise back to 3600 or higher
Common mistakes
- Thinking a low TTL makes a change appear instantly everywhere — it only limits how long old answers are cached, and some resolvers ignore very low values.
- Setting every record to 300 seconds permanently, which increases query volume without any real benefit.
- Forgetting that your registrar's nameserver TTL and your DNS provider's record TTL are separate settings.
