This Tool Lets You See How Every Website is Tracking You

This Tool Lets You See How Every Website is Tracking You
The Markup

We all know we’re being tracked online. That’s the business model of the “free” internet: a website remembers your friends birthdays or lets you upload selfies. In return, they get to hoover up every bit of information about and serve you ads. Fair trade? Well, people seem to do it! And what makes this tracking more palatable is that it tends to be fairly hidden.

But a new tool from the US online news publication The Markup brings the hidden side of adtech into the fore.

It’s just launched Blacklight, a website that bills itself as a “real-time website privacy inspector”. Or, in layman’s terms, a tool that shows you how websites are tracking you and who it’s sending it to.

According to Surya Mattu, who created the tool, and reporter Aaron Sankin, Blacklight was created to shine a light on the pervasiveness of online tracking.

“The Markup spent 18 months building a one-of-a-kind free public tool that can be used to inspect websites for potential privacy violations in real time,” they wrote in an article launching the tool.

“Blacklight reveals the trackers loading on any site—including methods created to thwart privacy-protection tools or watch your every scroll and click.”

What can Blacklight tell me about how websites are tracking me?

A user can plug any normal website into Blacklight to see what kind of user-tracking is being used.

The tool looks for ad trackers (used to identify or build up a profile on a user), third-party cookies (which work similar to ad trackers), and canvas fingerprinting (a type of tracking that works even if you block cookies). It even tells you whether the website is recording your clicks, scrolls, mouse movement and keystrokes.

A screenshot of The Markup's Blacklight, a tool for revealing website tracking
The Markup

After that, it’ll tell you whether the site is sending data to Facebook, Google or any of the other best known advertising technology companies.

After constructing the tool, The Markup looked at 80,000 of the world’s most popular website and found that more than 5,000 of them were “identifying them even if they block third-party cookies”. Yikes!

At the end of the day, there’s not much the average person can do to stop this even when armed with this normally opaque information. After all, it’s near impossible to avoid the biggest tech players online and live a normal life.

But even a little bit of insight might change how you decide to live your life online.