19 May 2026 · The DMARC Engine Team · 1 min read
DNS changes are not instant, but they are usually quick. Most updates apply within a few minutes to a couple of hours. In rare cases full propagation can take up to 24-48 hours.
What controls the speed
The main factor is TTL (time to live), a value set on each DNS record that tells resolvers how long they may cache the old answer. If a record had a TTL of 3600 seconds, a resolver that already cached it may keep serving the old value for up to an hour before fetching the new one.
So the practical rule is: the longest you should usually wait is roughly the previous record's TTL. New records that never existed before tend to appear almost immediately, because there was nothing cached to expire.
Why it can occasionally take longer
- Some resolvers and ISPs ignore short TTLs and cache more aggressively.
- Very high TTLs (a day or more) on an old record extend the wait.
- For brand-new domains, nameserver changes at the registrar level can take longer than ordinary record edits.
If you know a change is coming, lowering a record's TTL a day in advance shortens the eventual switchover.
How to check
Use our DNS propagation checker to query the record from multiple locations and confirm the new value is live. You can also re-run a lookup from our tools page.
For DMARC Engine setups, once your delegated CNAMEs resolve correctly, you are done, we manage the values behind them from that point on, so future policy changes do not require you to wait on DNS edits again.