Firefox is one of the most popular web browsers which has many built-in features and supports many number of add-ons. “BlockSite” is one of the Firefox add-on which is used to block list of websites in Firefox. We can also protect it by password, so that others cannot able change the setting or delete the websites without your access.


1 Open Firefox browser and click “Tools” and select Add-ons. Type “BlockSite” in the search bar at the top right corner of the window and press “Enter”.

2Wait for the page to load. In the search result, BlockSite will be on the first place. Click the “Install” button next to the BlockSite plugin. It will take less than 4 seconds to install according to your broadband speed. Once installation is complete, restart the Firefox browser.

3Go to Tools and select Add-ons. Click “Extensions” tab, you will find the list of plugin installed on your Firefox. Now click “Options” next to BlockSite plugin. A pop up window will open to configure the plugin as your need. By default, 3 check boxes checked and “Blacklist” radio button selected.

4Under “Authentication”, select “Enable Authentication” and type password in the below text field, which block others from changing the settings in BlockSite.

5Click “Add” button and enter the URL you want to block, and then click “OK”. Repeat this step to add more websites to block. Once you finished, click “OK”. Once you restart the Firefox, you can’t access the list of websites in the Blacklist.

Tips & Warnings

  • If you already exported the list of websites, then choose “Import” option to add the list of websites at a time instead of adding one by one.
  • In case if you forget the password, then type “about:config” in the Firefox address bar and press “Enter”. Right click on “BlockSite.authenticate” and select reset. This will remove the password for BlockSite plugin. Now you can get access to it without password.