Firefox 87 Introduces 'SmartBlock' Private Browsing Feature to Fix Websites Broken By Tracking Protections

Mozilla has released Firefox 87 for Macs, Windows, and Linux machines, introducing a new intelligent tracker blocking mechanism called SmartBlock.

Since 2015, Firefox has included a built-in Content Blocking feature that automatically blocks third-party scripts, images, and other content from being loaded from cross-site tracking companies in Private Browsing windows and Strict Tracking Protection Mode.

Mozilla recognizes that the feature sometimes blocks legitimate elements of websites which can cause them to malfunction. SmartBlock aims to provide a solution to this problem without compromising user privacy. From the company's blog:

In building these extra-strong privacy protections in Private Browsing windows and Strict Mode, we have been confronted with a fundamental problem: introducing a policy that outright blocks trackers on the web inevitably risks blocking components that are essential for some websites to function properly. This can result in images not appearing, features not working, poor performance, or even the entire page not loading at all.

To reduce this breakage, Firefox 87 is now introducing a new privacy feature we are calling SmartBlock. SmartBlock intelligently fixes up web pages that are broken by our tracking protections, without compromising user privacy.

Mozilla says SmartBlock works by providing local stand-ins for blocked third-party tracking scripts that behave "just enough" like the original ones to make sure that the website works properly.

The stand-ins come built-in to Firefox, so no third-party content from the trackers is loaded by the browser, meaning they can't track users this way. According to the developers, SmartBlock will silently stand in for several common scripts classified as trackers on the Disconnect Tracking Protection List, and should provide a noticeable performance improvement while browsing.

The previous version of the browser introduced Total Cookie Protection, which is designed to stop cookies from tracking users across the web. Firefox 87, the latest update, is available now from the Mozilla website.