Simply put, the Facebook Pixel is a Javascript code that you add to your website in order to track visitor activity. The Facebook Pixel is an analytics tool that helps you measure and increase the effectiveness of your advertising campaigns. This is done by reporting and analyzing the actions people take on your website. The Pixel uses this data to assign people to different target groups you can engage with ads in the future. The term “pixel” was not coined by Facebook. Tracking pixels and pixel advertising have already been around for quite some time. Initially, this solution was used for email marketing and was referred to as a “web beacon“. Nowadays, it became a standard in many online advertising platforms.

A tracking pixel is a graphic with dimensions of 1×1 pixels that is loaded when a user visits a website or opens an email. It’s so small that it’s barely noticeable. These tracking pixels were originally partly or fully designed to be transparent or camouflaged in the background color of the website so that they don’t stand out to users.

It relies on Facebook Cookies, which enable Facebook to match your website visitors to their respective Facebook user accounts. It loads a small library of functions that you can use whenever a website visitor takes a specific action that you want to track. These actions are called “conversions” and they are interpreted by the Pixel as “events”. These events can be Page Views, Add-to-Cart, Purchase, Scroll Depth, Time on Page, and more. The Pixel tracks URLs visited, domains visited, and devices your visitors use. You can view all these actions on your Facebook Pixel page. You can also use this data, later on, to advertise to people who visited your website. That’s called Retargeting.