What Is Flush DNS?

Flushing DNS means clearing the DNS cache stored on your computer, operating system, or browser. When you flush DNS, all previously saved domain-to-IP mappings are deleted, forcing your device to request fresh DNS information from authoritative servers.

This simple command often solves issues like:

  • Website not loading or redirecting to an old IP
  • DNS errors (DNS_PROBE_FINISHED_BAD_CONFIG, NXDOMAIN)
  • Connection problems after DNS or hosting changes

Test after flushing: use our DNS Lookup Tool to verify live DNS records.

What Is the DNS Cache?

A DNS cache is a temporary database your computer or router keeps to quickly resolve domain names. Instead of looking up DNS records every time, it stores recent responses for faster access.

Example:

When you visit example.com, your system remembers:

example.com → 93.184.216.34

TTL: 3600 seconds

If the website's IP changes before the TTL expires, you may still be directed to the old server until the cache expires — unless you flush DNS manually.

Why Should You Flush DNS?

Flushing DNS can fix a variety of network and browsing problems:

Problem Cause Solution
Website not loading or showing old content Cached IP address Flush DNS to fetch the updated record
DNS_PROBE_FINISHED_NXDOMAIN or BAD_CONFIG Corrupt or outdated cache Clear DNS to rebuild entries
Changed hosting or DNS records Old DNS still cached Flush DNS to see changes instantly
Privacy concerns Cached domain history Remove local DNS logs
SSL / HTTPS mismatch Old IP using invalid certificate Clear cache to get the correct host

If you've recently changed records, check DNS Propagation Status afterward.

How to Flush DNS on Different Systems

💻 Windows (10 / 11 / Server)

  1. Open Command Prompt (Run as Administrator)
  2. Type the following command and press Enter:
ipconfig /flushdns

You should see:

Successfully flushed the DNS Resolver Cache.

Optional:

View cache entries before clearing:

ipconfig /displaydns

🍎 macOS

  1. Open Terminal application
  2. Enter the command based on your macOS version:
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

Then press Enter. No confirmation appears, but DNS cache is cleared.

🐧 Linux

For systems using systemd-resolved:

sudo systemd-resolve --flush-caches

For older versions:

sudo /etc/init.d/nscd restart

or

sudo service dns-clean restart

Check cache statistics:

sudo systemd-resolve --statistics

📱 Android

Option 1:

Toggle Airplane Mode on and off (resets DNS cache).

Option 2:

Clear network settings:
Settings → Apps → Chrome (or Browser) → Storage → Clear Cache

Option 3 (advanced):

Use a DNS changer app to switch DNS (automatically clears cache).

📱 iOS (iPhone/iPad)

  • Toggle Airplane Mode on/off, or
  • Restart the device, or
  • Reset network settings:
    Settings → General → Transfer or Reset iPhone → Reset → Reset Network Settings

🌐 Web Browsers

Browser Method
Google Chrome Visit chrome://net-internals/#dns → Click "Clear host cache"
Microsoft Edge Visit edge://net-internals/#dns → Clear host cache
Mozilla Firefox Type about:networking#dns → Click "Clear DNS Cache"
Safari Close all windows → Clear history & caches (CMD + ALT + E)

Router-Level DNS Flush

Some routers also store DNS entries. To clear router DNS cache:

  1. Log in to your router's admin panel (e.g., 192.168.1.1)
  2. Navigate to Administration → System → Reboot / Restart
  3. Or look for a DNS Cache / Clear Cache option if available

Alternatively, simply restart your router to refresh its internal cache.

What Happens After Flushing DNS?

After a flush:

  • Your device discards all cached domain lookups
  • The next time you access a website, it queries the DNS server again
  • New IP data is cached freshly according to TTL values
  • It may briefly load slower (first query only), then speed returns

Example:

If your local cache had an old IP from before DNS propagation completed, flushing ensures you're now resolving to the current, correct server.

Flush DNS vs DNS Propagation

Concept Description Scope
Flush DNS Clears DNS cache on a single device Local
DNS Propagation Global update of DNS changes across servers Global
Result Forces fresh DNS queries Makes DNS changes visible globally

Learn more in What Is DNS Propagation?

When Should You Flush DNS?

✅ After:

  • Changing hosting provider or IP address
  • Updating DNS records (A, MX, CNAME, etc.)
  • Fixing SSL certificate or domain redirection issues
  • Experiencing DNS errors or slow website loads
  • Testing DNS propagation

💡 Pro tip:

If you use a VPN or proxy, flush DNS after connecting or disconnecting to avoid leaks.

Automated DNS Flush Tools (Windows & macOS)

Tool Platform Features
FlushDNS.cmd Windows Simple one-click batch script to clear DNS
CleanMyMac X macOS GUI-based DNS cache clearing under Maintenance
DNS Jumper Windows Switch DNS + flush with one click

You can also create your own script:

@echo off

ipconfig /flushdns

pause

FAQs

1. Is flushing DNS safe?

Yes. It only clears cached data; no network settings or passwords are affected.

2. Does flushing DNS improve Internet speed?

Temporarily yes, if old or corrupt entries were slowing lookups.

3. How often should I flush DNS?

Only when troubleshooting or after DNS changes—no need daily.

4. Can flushing DNS fix "site not found" errors?

Yes, often it resolves outdated or incorrect IP cache issues.

5. Does clearing browser cache flush DNS?

No, browser cache clears files; DNS flush specifically clears domain lookups.

Related Topics

What is DNS?

Learn about the Domain Name System and how it works

What is a DNS Server?

Understand DNS servers and their role in the internet

DNS Lookup Tool

Check DNS records for any domain

Reverse DNS Lookup

Find domain names from IP addresses

Ready to Test Your DNS?

After flushing your DNS cache, verify your domain's DNS records are resolving correctly with our free DNS Lookup Tool.

Try DNS Lookup Tool Explore All Tools
Subscribe Our Newsletter

We may log anonymized request data for diagnostics. Read our Privacy Policy.

Company
Resources
Legal
Social
heart

© 2025 DNS Lookup. All rights reserved. Proudly Hosted on MonoVM VPS Hosting

Privacy • Terms • Cookies • Security • Contact

We use HTTPS, HSTS, and regular security reviews. Report issues at [email protected]

If you believe a tool is being misused, report it at [email protected]