It's not unreasonable to expect that your online activities are kept secret. But tracking companies are able to monitor your browsing to build an accurate picture of who you are, your likes, and dislikes, your political leanings and your shopping habits.

This can be used to sell you stuff, to target political campaigns, or be sold elsewhere.

Traditionally, this profiling has relied on cookies—a technology which allows trackers to link up your behavior on multiple sites. However, a change by Firefox means that if you use the browser, cookies can't be used to trace users across the internet. But that won't make a difference for long.

What Is Firefox Total Cookie Protection?

While most people think that functional cookies ensures that websites and services run smoothly, many are becoming increasingly aware of the enormous privacy violations represented by third party cookies.

While it's relatively simple to block third party cookies in Chrome, Firefox, and Edge, you may feel nervous about poking around and making changes in your browser settings.

Firefox Total Cookie Protection was introduced in 2021 with Firefox 86, and works by creating a separate "cookie jar" for each website you visit. If any website or embedded content creates a cookie on your machine, it's kept in its own jar, and only the website which created it is allowed access.

This stops you from being tracked across the internet by third parties—if you turn the feature on.

Unfortunately, most people simply don't bother.

In April 2023, Firefox's parent organization announced on the Mozilla blog that Total Cookie Protection will be turned on by default for all users, meaning that if you can't be bothered to do it yourself, or you don't understand how, you'll be protected anyway.

How Do Tracking Companies and Cookies Work?

So why is Total Cookie Protection important? It's no secret that the companies gathering data on you right now make vast amounts of money from it.

The online advertising industry is huge; ensuring that users see adverts which are relevant to their interests, budget, and inclination is an art which keeps thousands gainfully employed. If you've been looking at flights and hotels in Mexico, then checking out articles on sun cream, you're an ideal candidate for serving an advert for swimsuits and beach footwear, for instance.

Every little scrap of information helps these companies to build a profile on you, and everything is scraped or inferred—from your device choice to your daily schedule and your dating profile.

Traditionally, your browsing data has been tracked using cookies. Cookies are small text files placed on your device, which contain a unique identifier. These are useful for keeping you logged in, updating your shopping cart, or acknowledging that you're a returning visitor.

Often, websites will drop third-party cookies on your device. These can be used to track you when you visit other websites, which you'd be forgiven for thinking is intrusive, creepy, and unethical.

Due to regulatory changes, sites using cookies must obtain your consent in certain jurisdictions, although this doesn't always happen.

How Else Can Tracking Companies Follow You?

While Firefox turning Total Cookie Protection on by default will help people from being tracked in the short term, the internet economy is already turning away from cookie-based tracking to keep tabs on you.

Read the privacy policy of any large publication, and you'll likely find a paragraph which reveals other technologies which are used to track you. This is invariably couched in vague and misleading language, and may refer to device scanning or fingerprinting.

Device scanning uses a number of metrics to assign you a unique identifier. They can track you using your IP address, time zone, operating system, the fonts you have installed, your screen resolution, battery information, language settings, and canvas draw time.

Taken on their own, none of these metrics will reveal who you are, but together, they create a reliable picture of you and your devices.

As Firefox and other browser companies take steps to restrict how much data can be gathered by cookies, tracking companies are moving faster towards more effective ways of tracking without cookies.

Internet Tracking Is an Arms Race

Tracking companies will always want to make money off you by whatever means necessary. You have to play the defensive game if you want to stay ahead. Fortunately, there are dozens of extensions for every browser which can help you to disguise yourself online.