View TTL for each record and estimate propagation wait.
TTL (Time To Live) on a DNS record tells resolvers how long they may cache it (in seconds). Low TTL (e.g. 300) means changes propagate faster but more DNS traffic; high TTL (e.g. 86400) reduces load but slows propagation after a change. This tool looks up the records you care about and shows the TTL for each. Use it before a DNS change to see how long you might wait for global propagation, or after a change to confirm new TTLs. Some tools also estimate "time until fully propagated" based on the maximum TTL seen.
For stable records (e.g. MX), 3600–86400 is common. Before a change, lower to 300–600; after propagation, raise again.
Each record has its own TTL. A and AAAA might be 300 while MX is 3600.
At most the previous TTL (caches expire by then). In practice, many resolvers update sooner; allow up to TTL to be safe.
Some providers allow 0 (no cache). Useful for quick testing; avoid long-term to avoid overloading DNS.
Indirectly. Lower TTL means more lookups; higher TTL means fewer lookups but slower propagation after changes.