Lower TTLs before a DNS migration
TTL decides how long resolvers keep an answer. Lowering it before a move gives you a fast way back, but only if you do it early enough.
Last updated September 24, 2026
The rule that trips people up
A lower TTL only takes effect after the old TTL expires. If a record has a TTL of one day and you lower it to five minutes, resolvers that fetched it this morning keep it until tomorrow morning. So lower TTLs at least one old TTL before the switch.
How low to go
300 seconds is a good target. Some providers enforce a floor: Cloudflare's is 60 seconds and GoDaddy's is 600. Going lower than a minute rarely helps, because many resolvers enforce their own minimum.
The TTL you can't change
The nameserver delegation lives in the parent zone at the registry, with the registry's TTL. For .com that's 48 hours. That's why the old provider must keep answering for at least two days after you switch, no matter how low your own TTLs are.
If both providers serve identical records, the switch itself doesn't need low TTLs at all. Low TTLs matter when you'll change record values at the same time, or want a quick rollback.
Negative caching
Resolvers also cache "this name doesn't exist" answers, for the SOA minimum value. If you'll add new records right after the switch, check that value too.
Raise them again afterwards
Once the move is done and stable, set TTLs back to an hour or more. Long TTLs mean fewer queries, faster lookups and more resilience if a provider has an incident.