Firefox rolls out Total Cookie Protection by default to more users worldwide

Take back your privacy

Firefox is rolling out Total Cookie Protection by default to more Firefox users worldwide, making Firefox the most private and secure major browser available across Windows, Mac, Linux and Android. Total Cookie Protection is Firefox’s strongest privacy protection to date, confining cookies to the site where they were created, thus preventing tracking companies from using these cookies to track your browsing from site to site.

Whether it’s applying for a student loan, seeking treatment or advice through a health site, or browsing an online dating app, massive amounts of your personal information is online — and this data is leaking all over the web. The hyper-specific-to-you ads you so often see online are made possible by cookies that are used to track your behavior across sites and build an extremely sophisticated profile of who you are.

Recent stories (including an excellent Last Week Tonight episode) have shown how robust, yet under-the-radar, the data selling economy is and how easy it is for anyone to buy your data, combine it with more data about you and use it for a variety of purposes, even beyond advertising.

It’s an alarming reality — the possibility that your every move online is being watched, tracked and shared — and one that’s antithetical to the open web we at Mozilla have strived to build. That’s why we developed Total Cookie Protection to help keep you safe online.

What is Total Cookie Protection?

Total Cookie Protection offers strong protections against tracking without affecting your browsing experience.

The top text reads: Total Cookie Protection. On the left side, the text reads: Before TCP. An illustration below shows three cookies over a browser window that say "" Below, two text boxes read: and On the right side, three separate browser windows contain one cookie each. The web address fields for the separate windows read:, and
Total Cookie Protection stops cookies from tracking you around the web.

Total Cookie Protection works by creating a separate “cookie jar” for each website you visit. Instead of allowing trackers to link up your behavior on multiple sites, they just get to see behavior on individual sites. Any time a website, or third-party content embedded in a website, deposits a cookie in your browser, that cookie is confined to the cookie jar assigned to only that website. No other websites can reach into the cookie jars that don’t belong to them and find out what the other websites’ cookies know about you — giving you freedom from invasive ads and reducing the amount of information companies gather about you. 

This approach strikes the balance between eliminating the worst privacy properties of third-party cookies – in particular the ability to track you – and allowing those cookies to fulfill their less invasive use cases (e.g. to provide accurate analytics). With Total Cookie Protection in Firefox, people can enjoy better privacy and have the great browsing experience they’ve come to expect. 

Total Cookie Protection offers additional privacy protections beyond those provided by our existing anti-tracking features. Enhanced Tracking Protection (ETP), which we launched in 2018, works by blocking trackers based on a maintained list. If a party is on that list, they lose the ability to use third-party cookies. ETP was a huge privacy win for Firefox users, but we’ve known this approach has some shortcomings. If a tracker for some reason isn’t on that list, they can still track users and violate their privacy. And if an attacker wants to thwart ETP, they can set up a new tracking domain that isn’t on the list. Total Cookie Protection avoids these problems by restricting the functionality for all cookies, not just for those on a defined list.  

A culmination of years of anti-tracking work

Total Cookie Protection is the culmination of years of work to fight the privacy catastrophe that stems from online trackers. We first began to block tracking in 2015 with the release of Tracking Protection, a feature people could turn on by going into Private Browsing mode. We recognized at that time that browser makers couldn’t just sit back and let their users be abused. In 2018, we introduced Enhanced Tracking Protection and turned it on by default for all Firefox users in 2019, reflecting our commitment to actively protect our users rather than expect them to protect themselves. Since then, we have continued to make progress towards blocking trackers and ending cross-site tracking by introducing protections against fingerprinting and supercookies

The release of Total Cookie Protection is the result of experimentation and feature testing, first in ETP Strict Mode and Private Browsing windows, then in Firefox Focus earlier this year. We’re now making it a default feature for all Firefox desktop users worldwide.

Our long history of fighting online tracking manifests itself in our advocacy to policy makers and other tech companies to reinforce their own privacy protections. We also push to make privacy an industry priority through our efforts in industry standards bodies when shaping the future of online advertising. Furthermore, we created the Privacy Not Included guide to simplify the very complicated privacy landscape and help consumers shop smarter and safer for products that connect to the internet.

Over more than a decade, Mozilla has proudly been leading the fight to build a more private internet. Bringing Total Cookie Protection to more Firefox users is our next step towards creating a better internet, one where your privacy is not optional.

Take back your privacy by downloading Firefox today.

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