How do I clear my OS and Browser DNS Cache?

Clearing Your OS & Browser DNS Cache or How to Flush DNS

Note: The info below clears your global Operating System DNS cache. Many browsers also cache DNS, but reset that Cache after a restart. Firefox does not always do this. Info on how to fix that is below.

Windows® 8

  1. Press Win+X to open the WinX Menu.
  2. Right-click on Command Prompt and select Run as Administrator.
  3. Type the following command and press Enter: ipconfig /flushdns
  4. If the command was successful, you will see the following message:
  5. Windows IP configuration successfully flushed the DNS Resolver Cache.

Windows 7

  1. Click the Start button.
  2. Enter cmd in the Start menu search field.
  3. Right-click on Command Prompt and select Run as Administrator.
  4. Type the following command and press Enter: ipconfig /flushdns
  5. If the command was successful, you will see the following message:
  6. Windows IP configuration successfully flushed the DNS Resolver Cache.

Windows XP, 2000, or Vista®

  1. Click the Start button.
  2. On the Start menu, click Run....
  3. If you do not see the Run command in Vista, enter run in the Search bar.
  4. Type the following command in the Run text box: ipconfig /flushdns

MacOS® 10.7 and 10.8

  1. Click Applications.
  2. Click Utilities.
  3. Double-click the Terminal application.
  4. Type the following command:
  5. sudo killall -HUP mDNSResponder
  6. ALERT! Warning: To run this command, you will need to know the computer's Admin account password.

MacOS 10.5 and 10.6

  1. Click Applications.
  2. Click Utilities.
  3. Double-click the Terminal application.
  4. Type the following command: sudo dscacheutil -flushcache

Specific Browser Caching

Firefox

We have found that Firefox can be especially aggressive about DNS caching. Here is some info that may help:
  1. type about:config in Firefox’s address bar
  2. acknowledge the warning that appears next
  3. find an entry called network.dnsCacheExpiration and set it’s value to 0
  4. if there’s no such entry, create a new integer item with the name above and a value of 0
  5. now go back and change the value to 3600

Other Browsers

The OS level DNS cache clearing should work for all other browsers.

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