Mozilla plans to introduce a new privacy feature in the upcoming Firefox 102 web browser. Called Query Parameter Stripping, it is designed to strip tracking parameters from web addresses to improve user privacy.
Mozilla integrated the privacy feature into Firefox Nightly 96 originally for testing purposes. Some sites and services add tracking parameters to links to track users across sites. Facebook, for example, adds a unique fbclid string to all outbound links, which is unique for all users of the site.
The parameter can be used to identify and track users. Facebook can use it if the service’s scripts are running on the target site, but others can also use it because the ID is unique.
One of the main advantages of using URL query string identifiers is that they don’t rely on cookies or other bits of data.
The initial release of query parameter stripping in Firefox 102 uses a blocklist to strip known tracking parameters from top-level URLs; this includes navigation events such as opening a new tab, clicking links, redirects, or window.open() events.
Mozilla decided to limit processing to top-level browsing events to reduce the likelihood of web compatibility issues. Browsing events on the same site are not processed because of this.
Browsing Tracking Protection is enabled in private browsing mode and when Firefox’s Advanced Tracking Protection feature is set to Strict. Firefox supports Standard (default), Strict, and Custom Enhanced Tracking Protection modes.
The privacy.query_stripping.enabled preference determines whether the feature is enabled or disabled in Firefox. Set the preference to TRUE on about:config to enable parameter removal.
Mozilla added support for custom settings that users can add to Firefox to automatically remove them along with the rest of the built-in removal. The privacy.query_stripping.strip_list preference accepts query strings and uses space as a delimiter.
brave navigator has a similar functionality that removes query strings from web addresses. The list used by Brave is public; it includes Facebook’s tracking strings, but also strings that other services use to track users across the web.
Firefox’s query string protection improves user privacy, but only in private browsing windows or when the browser’s Enhanced Tracking Protection setting is set to strict; this is a limitation, and most Firefox users may not benefit as much from the privacy enhancement because of it.
Still, it’s a step in the right direction, and it’s possible that Mozilla will enable the feature for standard mode as well. Most Firefox users may wish to switch to strict in-browser tracking protection, as this improves their privacy while using the browser.
Firefox 102 will be released on June 28, 2022.
Now you: Are you using your browser’s tracking protection features?