How to use Firefox’s new content blocking feature

Thanks to the Mozilla developers, Firefox has a new and improved content blocking system.

The Firefox developers are always working on ways to improve user experience. One area of focus lately is content blocking.


What is content blocking? According to Mozilla, content blocking is how a browser can work to:

  • Block third-party content that tracks you around the web.
  • Control how much of your online activity gets stored and shared between websites.

For the average user, content blocking functions as the first line of defense to prevent your data from being shared to third-party entities. Thanks to the Mozilla developers, Firefox has a new and improved content blocking system.

SEE: Server deployment/migration checklist (Tech Pro Research)

How do you use this much-improved feature? Let’s find out.

What you need

This new content blocking system came into being at the latest stable release, Firefox 65. I’ll demonstrate on a Nightly Build of Firefox, which is 67.Oa1 on Elementary OS. The platform you use doesn’t matter, so long as you work with Firefox 65 or newer.

How to get to content blocking

The developers have made getting to the content blocking feature incredibly easy. Open Firefox and click on the menu button (three horizontal lines in the upper right corner). In that menu, you’ll see an entry for Content Blocking (Figure A).

Figure A

Figure A: The Firefox Content Blocking Menu entry.

Click Content Blocking and a new tab will open to the feature settings.

Configuring Content Blocking

On the Content Blocking preferences page (Figure B), you’ll see three different “levels” of content blocking:

  • Standard – Blocks all known trackers, in Private Windows only, and prevents all third-party tracking cookies.
  • Strict – Blocks all detected trackers.
  • Custom – User chooses what to block.
Figure B

Figure B: The levels of content blocking in Firefox.

For most users, the Standard option will suffice, with the understanding that the only way to block trackers is by browsing in a private window. If that’s not enough for your needs, switch to Strict. The caveat with using the Strict level is that some websites may not function properly (as some sites depend upon tracking for certain functionality). If neither of these work, select the Custom option.

Custom blocking

In the Custom option, you can choose what is blocked. In the Custom configuration window (Figure C), you can enable/disable the blocking of Trackers and cookies. You can also select if trackers are blocked in only private windows or all windows. The blocking of cookies can be relegated to:

  • Third-party trackers.
  • Cookies from unvisited websites.
  • All third-party cookies.
  • All cookies.
Figure C

Figure C: The Custom content blocking options.

You should know this: If you select to block All third-party cookies, it may cause some websites to not function. If you select All cookies, it will cause some websites to not function. If you really need to block cookies and trackers, and you find certain, must-use, sites are broken, you can disable content blocking on a per-site base.

How do you do this? Let me show you.

Disabling Content Blocking for a site

When you visit a site (and you believe it’s not functioning, because of content blocking), click on the circled “i” in the left side of the address bar. From the drop-down menu (Figure D) click the Turn off Blocking for This Site button.

Figure D

Figure D: Turning off blocking on a per-site basis.

If you want solid content blocking in Firefox, you’ll need to make sure to disable content blocking for all the sites you work with (that you find are functioning improperly). Once you have your must-use sites unblocked, you can continue using Firefox with Strict or Custom content blocking enabled, knowing you can still get your work done.

A stronger system

The developers of Firefox have built a content blocking system that can be exactly what you want. Remember, however, if you want a stronger system of blocking, you’ll want to lean heavy on content blocking (such as Strict or Custom) and then disable the feature on a site-by-site basis. If you don’t want to mess with having to unblock sites individually, go with the Standard option and be done with it.