What is DNS propagation and how long does it take?
After a DNS change, it takes time for resolvers worldwide to update. This guide explains propagation, why it happens, how TTL affects timing,
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When you update a DNS record-change nameservers, update an A record, or modify an MX entry-the change doesn't appear instantly worldwide. DNS servers around the globe need time to update their cached records. This process is called propagation.
How long does it take?
| Change type | Typical time | Maximum time |
|---|---|---|
| DNS record update (A, MX, CNAME) | 5 minutes–1 hour | 24–48 hours |
| Nameserver change | 1–4 hours | 24–48 hours |
| Domain registration | 1–2 hours | 24 hours |
| Domain transfer (complete) | 2–7 days | 14 days |
While DNS propagates, your old site continues serving visitors whose resolvers have the old record cached. Your new site is already live on UnderHost-it's just not visible to everyone yet.
What is TTL?
TTL (Time To Live) is a number, in seconds, that tells DNS resolvers how long to cache a record before checking for updates. A TTL of 3600 means the resolver caches the record for 1 hour before checking for new values.
- High TTL (e.g. 86400 = 24 hours)-fewer DNS queries, but slower propagation when you make changes
- Low TTL (e.g. 300 = 5 minutes)-faster propagation, but more DNS queries
How to check propagation
To check the current DNS state for your domain, use the UnderHost DNS Check tool, the command-line DNS lookup tools mentioned below, or your registrar's propagation checker. You can see which resolvers have updated and which are still serving the old record.
Or check your own DNS cache:
nslookup yourdomain.com 8.8.8.8
This checks against Google's DNS (8.8.8.8) rather than your local resolver, giving a more accurate view of global propagation.
How to speed up propagation
- Lower your TTL before making changes-set it to 300 seconds (5 minutes) at least 24 hours before the planned DNS change. Resolvers will then only cache the old record for 5 minutes after you change it.
- Flush your local DNS cache-Windows:
ipconfig /flushdns| macOS:sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder - Try a different network-your mobile data (4G/5G) uses a different resolver than your home Wi-Fi and may have already propagated
Related: How to configure DNS for your domain | How to point a domain to UnderHost hosting | What nameservers should I use for UnderHost? | DNS record types explained-A, CNAME, MX, TXT, and more
Check DNS propagation
Use UnderHost DNS Check to verify nameservers, A records, MX records, TXT records, and propagation from one place.
