Blocking websites

How to Block Websites in Mozilla Firefox

Max. D Gray
By Max. D Gray. Updated: January 16, 2017
How to Block Websites in Mozilla Firefox

There are many reasons why you might want to block a website from your computer. The website might contain a virus that can infect your whole computer and jeopardize all of your files. Others could just be annoying pop-ups and some could contain explicit content that you don't want to see or that that you don't want your children to see. If you are a Mozilla Firefox user, blocking websites from the browser is quite easy. We'll tell you just how easy it is in this OneHowTo article, how to block websites in Mozilla Firefox.

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Steps to follow:


The easiest way of blocking websites in Mozilla Firefox is by using a free add-on called BlockSite. The BlockSite extension blocks sites which are added to its 'black list', but it can also be configured to disable links to blocked sites so that they don't work rather than showing their hyperlinks. BlockSite also has 'password protection' that helps prevent unwanted changes to BlockSite. To get BlockSite working, go through the following simple steps...

How to Block Websites in Mozilla Firefox - Step 1

For the first step, open Firefox, click 'Tools' and then 'Accessories'. Click 'Get add-ons' and then 'Browse all add-ons.' Type 'BlockSite' in the search bar after Mozilla Firefox opens and hit 'Enter.'


Next, click the 'Add to Firefox' button next to BlockSite. Allow the add-on to load (usually less than 5 seconds), then click on 'Install Now'. Restart Firefox when you are prompted.


Go to 'Tools' then 'Accessories' then click the BlockSite 'Preferences' button after restarting Firefox. Make sure the radio button 'blacklist' is checked and 'Enable BlockSite,' 'Enable warning messages' and 'Enable link removal.'


Type 'Allow authentication', then type a password if you want to prevent users from other blocked websites deleting or changing the settings in BlockSite without your permission.


Finally, click the 'Add' button, enter the URL of the website you want to block then click 'OK'. To add more sites, repeat this process, or to clear the list, click the 'Clear' button. Once the list of blocked sites is complete, click 'OK' and restart Firefox.

How easy was that!? Now you will be able to browse with Mozilla Firefox and be free from any unwanted websites.

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  • To import a list of pre-prepared or exported blocked web sites , click the 'Import' button in the Preferences window, find the file you want to import and click 'OK'. The file should show "[BlockSite]" at the top of the page followed by the URLs of sites you want to block.
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How to Block Websites in Mozilla Firefox