What Websites Know About You

Note: This is a guest post written by @gooca and contributed during Hacktoberfest.

The Internet:

A beacon of freedom, the home of anonymity, a safe haven for privacy.

You may think that unless you hand over your anonymity to the internet giants such as Facebook or Google, your privacy would be intact. You would be wrong.

Just kidding (mostly). However, you may be surprised at some information that your browser tracks that can be accessed by any website. Most of the “features” to be discussed are extremely useful to web developers, whether for statistical purposes or customizing the user experience. However, this doesn’t mean that this data can’t be used for more nefarious purposes, like tracking. Here are a few things every website knows about you.

♪ Where did you come from, where did you go? ♪

Websites have access to the previous page you visited before you accessed the current website. For example, if you clicked on a link on reddit.com, the website knows the link you visited on reddit before you clicked on their website.


This one may be pretty obvious to you. Whether through looking up your ip, or using a geolocation API, websites have access to your location. This is how you get the “Did you login from {location}?” emails when you access accounts on vacation. The location information is not ridiculously accurate, but it is close enough.

Social Media

Website can also tell if you are logged into social media. Facebook, Google, Instagram, all can be analyzed to see what social networks you have accounts on, and deductively, what social networks you don’t.

Device Information

Hardware information like which Operating System, number of CPU cores, graphics card, and monitor resolution are all available for tracking. Additionally, the battery level of your device is trackable. When the battery level is paired with hardware information and location, this makes for a very viable tracking method, since all of this information can be unique.

That’s all I’m going to be discussing! For more information and some cool privacy plugins, check out the source of this information.