root `index` legacy
User Tracker An aggressive user tracker without any client-side logic. Explaining how it works and telling you how you can try to bypass it. `2021-08-10` GitHub • Try it Overview User Tracker is a webpage that assigns every user a unique ID and tracks them regardless of which device or IP address they are using. It is ideal for specific applications such as a ban tracking system. Click here to view it! How it Works This tracker is decievingly simple but surprisingly effective. When a user visits a website, the web browser automatically sends some information to the server to help it respond to the request. It includes the following: The browser user agent The user's public IP address The cookies saved by the website The server then uses a user agent parser along with an IP lookup library to extract the following data from the user: Operating system name and version Device vendor, model and type CPU architecture Browser name and version User region, city, longitude and latitude Device timezone Browser cookies Finally, the server runs the acquired data against its database. If the current user data is similar enough to a known user, they are considered to be the same. If no match is found, a new entry is created for the current user. To improve user tracking further, the server uses a clever trick to detect wether a user is trying to evade it. In short, when the current user data is not an exact match to the data stored in the database, the back-end code keeps track of all the descrepencies. It remembers which device you are using. In fact, it remembers every device you ever used. If you use a VPN, it will know. If you go in Incognito mode, it will know. If you clear your cookies, it will know. If you want to try to fool this user tracker for yourself, just click here! What I Learned I didn't really learn any new technologies when creating this tracker. I programmed a rough back-end and, when I saw how well it worked, I quickly glued together a front-end page. However, I did learn how to `set` and `get` cookies directly from the server, so there's that. This program reminds me of another project of mine, called WebInfo. Before creating it, I didn't know just how much information a webpage could collect without any user interaction. Now that I programmed User Tracker, I understand how easy it is to track users without them even knowing about it. Moving forward, I will approach online anonymity with a lot more care.
© 2025 Emilien Breton `legacy/User-Tracker/index.md`

User Tracker

An aggressive user tracker without any client-side logic. Explaining how it works and telling you how you can try to bypass it. 2021-08-10

GitHub • Try it

Overview

User Tracker is a webpage that assigns every user a unique ID and tracks them regardless of which device or IP address they are using. It is ideal for specific applications such as a ban tracking system. Click here to view it!

How it Works

This tracker is decievingly simple but surprisingly effective.

When a user visits a website, the web browser automatically sends some information to the server to help it respond to the request. It includes the following:

The browser user agent
The user's public IP address
The cookies saved by the website

The server then uses a user agent parser along with an IP lookup library to extract the following data from the user:

Operating system name and version
Device vendor, model and type
CPU architecture
Browser name and version
User region, city, longitude and latitude
Device timezone
Browser cookies

Finally, the server runs the acquired data against its database. If the current user data is similar enough to a known user, they are considered to be the same. If no match is found, a new entry is created for the current user.

To improve user tracking further, the server uses a clever trick to detect wether a user is trying to evade it. In short, when the current user data is not an exact match to the data stored in the database, the back-end code keeps track of all the descrepencies.

It remembers which device you are using. In fact, it remembers every device you ever used. If you use a VPN, it will know. If you go in Incognito mode, it will know. If you clear your cookies, it will know.

If you want to try to fool this user tracker for yourself, just click here!

What I Learned

I didn't really learn any new technologies when creating this tracker. I programmed a rough back-end and, when I saw how well it worked, I quickly glued together a front-end page. However, I did learn how to set and get cookies directly from the server, so there's that.

This program reminds me of another project of mine, called WebInfo. Before creating it, I didn't know just how much information a webpage could collect without any user interaction. Now that I programmed User Tracker, I understand how easy it is to track users without them even knowing about it. Moving forward, I will approach online anonymity with a lot more care.