What is particles.js?

particles.js is a lightweight JavaScript library that adds animated, interactive floating particles to a web page background. You have likely seen this effect on websites where small dots or shapes drift around the screen, sometimes connecting with lines or reacting when you hover your mouse over them. This library makes it straightforward to add that visual effect without writing complex animation code yourself. To use it, you add one HTML element to your page, load the library script, and then point it at a JSON configuration file where you set all the visual details: how many particles appear, their color, shape (circles, triangles, polygons, stars, or custom images), size, speed, and direction of movement. You can also control interactivity, for example, particles can scatter away from the mouse cursor, grow larger when hovered, or new ones can appear when you click. The configuration is entirely data-driven, so no code changes are needed to adjust the look and feel. You would use this when building a landing page, portfolio site, or login screen where you want a dynamic, modern background effect without pulling in a large dependency. The library is written in JavaScript and can be installed via npm, included from a content delivery network, or added directly as a script tag in your HTML.