What is Flush DNS? How to Clear DNS Cache on Windows, Linux, MacOS

Surely you have "gone crazy" many times when your computer cannot access the web because of errors such as  404 page not found  or  502 bad gateway . Flush DNS or delete DNS will be a method to help you fix these errors quickly. So how to flush DNS on Windows, Linux or MAC operating systems? Let's  find out with TipsMake ! 

What is DNS Flush?

Flush DNS is to clear the DNS cache. Why do you have to do this when this memory helps you access the web faster? Because when websites change their IP address or switch to another web server and your DNS cache has not been updated, errors will definitely occur. Even if   there is nothing unusual  about the internet , you still cannot access the website with typical errors such as 404 page not found . Therefore, clearing the DNS cache will help your computer update the web information and successfully access that website. So how to flush DNS? Each operating system will have a different way of doing it, please see the next section!

What is DNS Cache?

DNS cache is a system that temporarily stores IP addresses corresponding to domain names that users have visited. When a user visits a website for the first time, the browser sends a request to the DNS server to resolve the domain name into an IP address.

This IP address is then stored in the DNS cache on the user's computer to speed up access for subsequent visits without having to perform the query process again.

The DNS cache stores information in the form of records, including the IP address and the Time to Live (TTL) of each record. The time to live determines how long the record will remain valid in the cache before it needs to be refreshed. When a website changes its IP address, flushing the DNS cache (also known as flushing DNS) is necessary to ensure that users can access the new address without errors.

How to flush DNS on Windows operating system

To clear DNS on a Windows computer, follow these simple steps:

Step 1: Before flushing DNS, close all applications on your computer. First, go to the Start menu, go to the search box and type "cmd" then press enter. Or you can press the Windows R key combo to open the Run dialog box and type "cmd". 

Step 2: Now Windows command prompt will appear. You type " ipconfig /flushdns " into it and press enter. Wait a moment, Windows command prompt will display the result " Successfully flushed the DNS Resolver Cache ". That means the DNS cache has been successfully flushed. Now you can try reloading the website to see if the error has been fixed.

If flushing DNS does not fix the error, try disabling the DNS cache completely to see if it helps. To do that, follow these steps:

Step 1: Open Windows command prompt as instructed above by pressing Windows R to open the Run dialog box , type " cmd " and press Enter.

Step 2: Enter the following command " sc servername stop dnscache " or " net stop dnscache " and press Enter. This will disable the DNS cache until the computer restarts. Now reload the website to see if the network error has been fixed.

How to flush DNS on MacOS

Each version of MAC operating system will have a different way to flush DNS, but in general, all follow the following steps:

Step 1: Open Finder, go to Applications, Utilities and select Terminal.

Step 2: Type the following command (depending on the operating system version):

- For Mac OS 10.10.4 and higher versions:

sudo killall -HUP mDNSResponder

- For MacOS 10.10.1, 10.10.2, 10.10.3:

sudo discoveryutil mdnsflushcache

- For Mac OS 10.7, 10.8, 10.9:

sudo killall -HUP mDNSResponder

- For Mac OS 10.5, 10.6:

sudo dscacheutil -flushcache

To execute the above command, you need the password of the Admin account on the machine. If the DNS cache clearing process is successful, the system will not give you any notification. Go to the website and reload to see if the error has been fixed!

How to flush DNS on Linux operating system

A popular application for flushing DNS on Linux is the Name Service Caching Daemon (NSCD for short). You can clear the Local DNS cache by restarting NSCD via the following command in the terminal:

sudo /etc/init.d/nscd restart

If you use Ubuntu Linux, you can use the following command:

sudo service network-manager restart

Press enter to execute the command and then the DNS cache will be cleared.

How to disable Firefox

To disable Firefox, you can follow these steps:

Step 1: Close the browser:

1. Click the "X" button in the upper right corner of the Firefox window to close the browser.

Step 2: Uninstall Firefox (if you want to remove it completely):

1. Open the Start menu on Windows.
2. Select "Control Panel".
3. Find and select "Programs and Features".
4. Find Mozilla Firefox in the list, right-click and select "Uninstall" to uninstall.

Step 3: Turn off sync (if you don't want to use this feature):

1. Open Firefox, click the menu and select "Preferences" or "Settings".
2. In the "Sync" section, turn off the sync option.

Step 4: Disable extensions:

If you just want to temporarily stop using Firefox without uninstalling it, simply close the browser.

In the Extensions tab, you can disable or remove unnecessary extensions.

Above are some knowledge about how to clear DNS cache to help fix the error of not being able to access the web. Hopefully the article has helped you know how to flush DNS on different operating systems. Leave your email below to receive useful technology articles from TipsMake! 

Source: TipsMake share

Micah Soto

Update 12 February 2025