What is TTL (time to live)?

How long, in seconds, resolvers may cache a DNS answer.

A TTL of 300 means caches keep the answer for five minutes. Lowering TTLs before a migration makes the switch-over faster.

Related terms

• CAA record: A DNS record that lists which certificate authorities may issue certificates for a domain.
• DNSSEC: Cryptographic signatures that let resolvers verify DNS answers weren't tampered with.
• SPF: Sender Policy Framework: a TXT record listing which servers may send email for a domain.