Your DNS cache stores IP addresses of webservers. These servers have delivered pages which you and others have recently viewed. If the location of the web server changes for any reason before the entry in your DNS cache automatically updates, you will find yourself unable to access the website. You may also see a lot of 404 error codes, which generally happens when your DNS cache is messed up.
This is particularly prevalent for Webmasters who are setting up a new website and suddenly get presented with an old page or no page at all. Often it is visble on another computer or mobile phone which makes it even more frustrating.
By clearing this DNS cache, your computer will then re-query the nameservers for the new DNS information.
How to clear your computer’s DNS cache in Windows 2000, XP, Vista, 7 or 8
- Click the Start button
- On the Start menu, click Run
- If you do not see the Run command in Vista/7/8, enter “run” in the Search bar just above the start orb
- Type the following in the Run text box: ipconfig /flushdns
- Press Enter
Pay attention to the space between the g and the forward slash.
Close the command window and retry your browser.
How to clear your computer’s DNS cache in Mac OS 10.7 onwards
Please note that for this to work you require the Admin account password.
- Click Applications
- Click Utilities
- Double click the Terminal application
- Type in: sudo killall -HUP mDNSResponder
Close the terminal window and retry your browser.
How to clear your computer’s DNS cache in Mac OS 10.6 and below
- Click Applications
- Click Utilities
- Double-click the Terminal application
- Type in: dscacheutil -flushcache
That’s it and you should now be able to fire up your browser and get a fresh version of the page.