Firefox Starts Blocking Cross-Site Tracking By Default in Private Browsing

Mozilla has extended its protection against cross-site tracking for all Firefox users accessing the Web through Private Browsing windows. The change comes through a security feature called Total Cookie Protection that is enabled by default on Firefox 89 — the latest version. Mozilla claimed that its Total Cookie Protection is based on a principle that restricts the Firefox browser from sharing Web cookies between websites and keeps them separately in different “cookie jars” to help protect user identity to some extent.

Total Cookie Protection was first provided to users who have enabled the strict Enhanced Tracking Protection (ETP) mode on Firefox 86 in February. However, Mozilla has now extended its availability and enabled it by default for all users on Firefox 89.

By enabling Total Cookie Protection by default, Mozilla said in a blog post that each website you visit in a Private Browsing window will be given a separate cookie jar where Firefox will keep cookies continued to that site only. This is unlike the traditional approach in which Web browsers allow websites to share cookies.

“Total Cookie Protection covers not just cookies but a variety of browser technologies that previously were able to be used for cross-site tracking,” the nonprofit organisation said.

However, there are some exceptions. Mozilla said that the new feature does allow sharing of cookies between websites when they are needed for cross-site logins and any similar cross-site functionality.

You are not required to perform any specific actions to get the new security environment, and all you need to do is to switch to a Private Browsing window to get Total Cookie Protection into place. You can open a Private Browsing window by clicking on the Application Menu button and then choosing the New Private Window option. Alternatively, you can press CTRL+ SHIFT + P on a Windows machine or CMD + SHIFT + P on a Mac computer to switch to a Private Browsing window.

In addition to Total Cookie Protection, Firefox has enabled a list of features by default when using private browsing sessions. These include supercookie protections that stop supercookies from following you from one site to another and SmartBlock that fixes up web pages that were previously broken when tracking scripts were blocked.

The browser in Private Browsing also blocks elements including cookies, scripts, tracking pixels, and other resources from domains on Disconnect's list of known trackers. It also restricts fingerprint scripts and clears cookies as well as caches once the private browsing session ends.

Alongside the default protection layer against cross-site cookie sharing, Firefox 89 comes with a redesigned experience that brings a cleaner Web browsing experience. It has detached tabs and simpler navigation. The updated browser is available for download on desktops.