DNS Propagation
The time it takes for DNS changes to spread across all servers worldwide.
When you make DNS changes, they don't take effect instantly everywhere. DNS propagation is the process of these changes spreading across the global network of DNS servers.
Why Propagation Takes Time:
- DNS servers cache records based on TTL
- Old cached values must expire
- Then servers fetch new values
- This happens gradually worldwide
Factors Affecting Speed:
- TTL value: Lower TTL = faster propagation
- DNS provider: Some update faster than others
- Location: Some regions update slower
- Record type: Some propagate faster than others
Typical Timelines:
- Most locations: 15 minutes to 4 hours
- Some locations: Up to 24 hours
- Full global: Up to 48 hours
Speeding Up Propagation:
- Lower TTL to 300 (5 min) 24-48 hours before changes
- Make your changes
- Wait for propagation
- Raise TTL back to normal
Checking Propagation:
- whatsmydns.net - Check from multiple locations
- dnschecker.org - Similar multi-location check
- dig command - Technical DNS query tool
Why It Matters
Understanding propagation prevents panic when DNS changes don't work instantly. It helps you plan migrations and set expectations for when changes will be fully live.
Practical Example
You update your A record to point to a new server. It works immediately for you, but your colleague in another city still sees the old site. Over the next few hours, more locations see the new server as propagation completes.
Related Terms
A Record
TechnicalA DNS record that maps a domain name to an IPv4 address.
DNS (Domain Name System)
TechnicalThe system that translates domain names into IP addresses.
Nameserver
TechnicalA server that stores DNS records and responds to queries about domain names.
TTL (Time to Live)
TechnicalA setting that controls how long DNS records are cached before being refreshed.
Explore More Terms
Browse our complete glossary of domain name terminology.