Flush DNS Cache

Modern browsers, OS, and DNS clients store cache of IP addresses and other DNS information automatically. When a computer visits a website for the first time, it stores the website's DNS information in the cache, and on the next visit of the same website, it looks in the cache to see if the web site's information is present to use. An old version of a site opens if the website's DNS information has changed since the computer's last visit.

Flushing the cache removes all the data stored in the cache, forcing the computer to find the new DNS information for the website. It is usually done to speed up the process and minimize requests for the same hostnames. When IP addresses are changed, or bad results are cached, its necessary to clear the DNS cache. DNS cache can be cleared via command line or from browsers also. Steps to flush DNS Cache for major operating systems and browsers are as below.

Windows

How to Flush DNS in Windows 10?

Command Prompt and Windows Powershell, which is a new addition to Windows, can be used to clear DNS cache.

Option 1 – Command Prompt

To reset the DNS resolver cache, perform the following steps:

1. Click the Start button, then type cmd
2. Right-click Command Prompt, then choose Run as Administrator.
3. Type ipconfig /flushdns then press Enter. (be sure there is a space before the slash)

A command box will flash on the screen for a split second, and the DNS Resolver cache is cleared.

Besides, there are some other related commands that you might be interested in:

• ipconfig /displaydns: It displays your current DNS cache under Windows IP configuration.
• ipconfig /registerdns: To register your DNS cache recorded in the Hosts file.
• ipconfig /release: To release the current IP address settings.
• ipconfig /renew: To reset and request a new IP address.

Option 2 – Windows PowerShell

1. Select the Start button, then type powershell
2. Select Windows PowerShell
3. Type the following command, then press Enter:
4. Clear-DnsClientCache

How to Flush DNS in Windows 8 and 8.1?

Because of the system security policies run cmd as administrator user and follow below steps to flush DNS cache.

1. Press Windows key + X and select the Command Prompt (Admin) option from the Power User menu.
2. Type in the command ipconfig /flushdns and press Enter

How to Flush DNS in Windows 7 and Windows Vista?

To flush DNS on an upgraded version of Windows is almost as easy as it is in the previous versions but due to Microsoft's upgraded security system requirements, you must run the command prompt with administrator privileges.

1. To flush DNS through the command prompt, navigate as shown (Start > All Programs > Accessories > Command Prompt)
2. to have administrator privileges, you must do right click on the command prompt application and choose Run as Administrator.
3. Type in the command ipconfig /flushdns and press Enter

Shortcut

Type in cmd into the Windows Vista / Windows 7 start menu search field and then right click on the cmd.exe result instead of navigating through the various sub-menus.

Windows 98/NT/2000/XP Flush DNS

Given below steps will help you to clear your windows DNS cache.

1. To access command prompt (Start > Run >).
2. Type the cmd and hit Enter
3. In the CMD window that you just opened, Type in the command ipconfig /flushdns

Mac OS

Flushing the DNS in Mac OS X is an easy process, but the steps taken will depend on which version of OS X is running as your operating system. First, make sure you open the Terminal on your computer. Once opened, run the command below that corresponds to your version of OS X.

macOS 11 (Big Sur)

macOS 10.15 (Catalina)

macOS 10.14 (Mojave)

macOS 10.13 (High Sierra)

OS X 12 (Sierra) and later

OS X 11 (El Capitan) and OS X 12 (Sierra)

OS X 10.10 (Yosemite)

Versions 10.10.4+

Versions 10.10.1, 10.10.2, 10.10.3

OS X 10.9 (Mavericks)

OS X 10.7 (Lion) and 10.8 (Mountain Lion)

OS X 10.5 (Leopard) and 10.6 (Snow Leopard)

OS X 10.4 (Tiger)

Linux Flush DNS

Ubuntu & Debian

Most Ubuntu and Debian systems run a system that uses systemd-resolve daemon; you will need to do the following.

1. Open up a command terminal (either as root or run with sudo)
2. Run the command in the terminal: systemd-resolve --flush-caches
3. Optional. You can verify that this ran correctly by running the command: systemd-resolve --statistics

Others

If you are running the nscd Name Service Cache Daemon, then you will need to do the following.

1. Open up a command terminal (either as root or run step 2 with sudo )
2. Run the command in the terminal: /etc/init.d/nscd restart

Mobile Devices

iPhone

There are three options available to flush DNS cache in iPhone.

Toggle the Airplane mode

The easiest solution is to toggle the Airplane mode in iPhone. For this

1. Open the "Settings".
2. You will see the icon of an airplane. Click that to toggle on.
3. Again click that icon to toggle off.

Reboot your iPhone

• Rebooting your device also clears your DNS cache.

Dump Network Settings

That will clear your DNS cache but will also immediately disable your Wi-Fi connection.

1. Open the "Settings".
2. Click on "General".
3. Click "Reset", then "Reset Network Settings".
4. Your device is then rebooted. 

iOS Devices

1. Press and hold both the Sleep/Wake and Home buttons for at least 10 seconds, until you see the Apple logo.

Android

Flush DNS cache in Chrome

Open the Chrome browser

1. In the URL bar, type in chrome://net-internals/#dns
2. In the left pane, click "DNS".
3. In the right pane, click the "Clear host cache" button.

Clear the cache of your browser

In your android phone

1. Go to Settings > Apps.
2. Select the browser app you are using.
3. Here go to "Storage" and tap on "Clear Cache".

Use Wi-Fi to Remove DNS Cache

1. Settings on your Android device.
2. Open Wi-Fi and then long-press the network you want to modify DNS for.
3. Tap on "Modify network".
4. A pop-up will appear, and you need to tap on "Advanced options".
5. Select IP settings as "Static". By default, it should be DHCP.
6. Go to DNS settings and manually enter the DNS servers. It is better to use Google DNS.
7. In DNS 1: enter the primary DNS server, and in DNS 2: enter the secondary DNS server.
8. Save your settings.

TV Devices

1. Step 1. Close apps: Close the app completely. Make sure it is not running in the background as well.
2. Step 2. Open App: Open the app again. DNS Cache should is cleared.

Google Chrome Browser

This method can be used for the Chrome browser regardless of the operating system.

1. Start Google Chrome.
2. In the address bar, type chrome://net-internals/#dns. Google Chrome displays a list of hosts in its internal DNS cache.
3. Click Clear host cache.
4. In the address bar, type chrome://net-internals/#sockets.
5. Click Close idle sockets, and then click Flush socket pools.

For Webmasters/ Developers

DNS cache can be cleared on the client-side, but the same can be done on DNS Serves aswell to speed up the DNS Propagation process. It can be achieved in the following ways:

Public DNS services like Google, Cloudflare, OpenDNS, VeriSign enable users to request a DNS flush for specific domains.

Google Public DNS:

1. Visit Google's Public DNS Flush Cache page.
2. You'll see a page with content similar to this:
3. 

Cloudflare Public DNS

1. Visit the Cloudflare purge Cache page.
2. You'll see a page with content similar to this:
3. 

OpenDNS PublicDNS

1. Visit the OpenDNS Cache check page.
2. It will display DNS results from its multiple server locations. At the bottom, press the Refresh The Cache button to clear the DNS cache.

Reduce TTL

1. TTL can be defined in your DNS settings. DNS servers respect TTL and reducing TTL can speed up the process of DNS propagation when changing servers IP's of a web application.