When you update your domain’s DNS records – whether you’re changing your web host, updating an IP address, or setting up a new email service – the changes don’t appear everywhere at once. This delay is called DNS propagation.

What Is DNS Propagation?

DNS propagation is the time it takes for updated DNS records to spread across all the name servers on the internet. Think of it as the internet updating its address book: your authoritative nameservers have the new information, but every other DNS server around the world still has the old copy cached.

This process normally takes anywhere from a few minutes to 48 hours, depending on several factors.

How It Works 

flowchart LR
    A["You Change IP"] -->|Update| B["Authoritative DNS"]
    B -->|TTL Expired| C["ISP Cache Node"]
    B -->|TTL Expired| E["Google DNS"]
    C -->|Serves New IP| D["User in London"]
    E -->|Serves New IP| F["User in New York"]

    style A fill:#fff3e0,stroke:#f57c00,color:#1a202c
    style B fill:#fff3e0,stroke:#f57c00,color:#1a202c
    style C fill:#e3f2fd,stroke:#1976d2,color:#1a202c
    style D fill:#e3f2fd,stroke:#1976d2,color:#1a202c
    style E fill:#e3f2fd,stroke:#1976d2,color:#1a202c
    style F fill:#e3f2fd,stroke:#1976d2,color:#1a202c

Here’s what happens when you change a DNS record:

  1. You make the change. You update a record (an A record, CNAME, MX record, etc.) through your hosting control panel or domain registrar.
  2. Your authoritative nameserver updates immediately. The server responsible for your domain now has the new record.
  3. ISP and recursive resolvers check in. DNS servers around the world periodically ask your authoritative server for fresh data. Until they do, they keep serving the old cached version.
  4. The old cache expires. Each DNS record has a TTL (Time to Live) value. Once the TTL expires, the resolver fetches the updated record.

The time between step 2 and step 4 is what people call propagation.

What Affects Propagation Speed?

FactorWhat It Means
TTL (Time to Live)A value (in seconds) that tells DNS servers how long to cache a record before checking for updates. A TTL of 3600 means servers cache the record for 1 hour.
ISP cachingSome ISPs ignore TTL values and refresh their DNS caches on their own schedule, which can be slower.
Record typeSimple A record changes propagate faster than nameserver (NS) changes. Changing nameservers involves updating the TLD registry, which adds time.
Geographic distanceA DNS server in London might pick up the change before one in Sydney simply because of how resolver chains work.

Pro tip: Lower your TTL before making changes. If you’re planning a migration, lower your TTL to 300 seconds (5 minutes) at least 24 hours before the move. This way, once you make the switch, DNS servers worldwide will check for updates every 5 minutes instead of every few hours.

Why Am I Seeing the Old Site?

It’s common for one person to see the new site while another person still sees the old one. This usually happens because:

  • Your browser cache is still serving the old IP address. Try opening the site in an incognito/private window.
  • Your OS DNS cache hasn’t expired yet. Your computer stores DNS lookups locally and reuses them until they expire.
  • Your ISP’s resolver hasn’t updated yet. ISPs cache DNS records on their own servers, and some are slower than others.

How to Flush Your Local DNS Cache

You can force your computer to forget its cached DNS records and fetch fresh ones.

Windows

Open Command Prompt (or PowerShell) and run:

  ipconfig /flushdns

You should see: Successfully flushed the DNS Resolver Cache.

macOS

Open Terminal and run:

  sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

Enter your password when prompted.

Linux

The command depends on your distribution:

  # Ubuntu / Debian (systemd-resolved)
sudo systemd-resolve --flush-caches

# Or on newer Ubuntu versions
sudo resolvectl flush-caches

After flushing, open your browser in a private window and visit the site to check whether the new DNS records have reached your location.

How to Check Propagation Progress

Use these free online tools to see whether your DNS changes have propagated to servers around the world:

Wait for the full 48 hours. While most updates finish within a few hours, give it the full 48 hours before assuming something is wrong. If records haven’t updated after 48 hours, double-check that you’ve saved your changes and that the correct nameservers are active.

Quick Reference

ScenarioTypical Propagation Time
A record change (same registrar)5 minutes to 4 hours
MX record change1 to 12 hours
Nameserver change12 to 48 hours
New domain registration1 to 24 hours
TTL pre-lowered to 300sUnder 10 minutes

Last updated 14 Apr 2026, 08:40 +0300. history

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