The Facebook pixel is an analytics tool that lets you track how people interact with your website to determine how efficient your advertising is. It also ensures your ads are shown to the right people, increases your sales, and measures your ad’s effectiveness. The Facebook pixel is a piece of code that you add to your site. It gathers information that allows you to measure conversions from Facebook advertisements, improve campaigns, create targeted audiences for future ads, and remarket to those who have already visited your website.