DNS propagation is the time it takes for DNS changes to spread across the internet. During this period, different users may see different results.
What is DNS Propagation?
When you change a DNS record:
- You update the record at your DNS provider
- DNS servers worldwide need to get the new information
- Old cached records expire based on TTL
- Eventually all servers have the new record
How Long Does Propagation Take?
| Change Type | Typical Time | Maximum Time |
|---|---|---|
| A record change | 1-4 hours | 48 hours |
| Nameserver change | 12-24 hours | 48-72 hours |
| New subdomain | Minutes to hours | 24 hours |
| TXT record | 1-4 hours | 48 hours |
What Affects Propagation Time?
TTL (Time to Live)
TTL tells DNS servers how long to cache a record:
- Low TTL (300 seconds): Faster propagation, more DNS queries
- High TTL (86400 seconds): Slower propagation, fewer queries
Lower your TTL before making changes, then raise it after.
ISP DNS Caching
Some ISPs cache DNS longer than specified TTL. You cannot control this.
Browser and OS Caching
Your computer and browser also cache DNS. Clear these caches to see changes faster.
Checking Propagation Status
Use these tools to check propagation worldwide:
These show DNS results from servers in different locations.
Speeding Up Propagation
Before Making Changes
- Lower TTL to 300 seconds (5 minutes)
- Wait for old TTL to expire (e.g., if TTL was 14400, wait 4 hours)
- Make your DNS changes
- After propagation, raise TTL back to 14400 or higher
Clear Local DNS Cache
Windows:
ipconfig /flushdns
Mac:
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
Chrome:
chrome://net-internals/#dns > Clear host cache
During Propagation
- Some users see old site, some see new
- Email may go to old or new server
- Avoid making additional changes
- Keep old server running until fully propagated
Common Propagation Issues
Site shows old content
- Clear browser cache
- Try incognito/private mode
- Try different network (mobile data)
- Wait for propagation to complete
Works for some, not others
This is normal during propagation. Different locations update at different times.
Still not working after 48 hours
- Verify DNS records are correct
- Check nameservers are correct
- Ensure domain is not expired
- Contact support for assistance