Lottie.js is a JavaScript library that makes it simple for developers to create and use high-quality animations for web, mobile, and desktop applications. Lottie.js was created by Airbnb to address the difficulties in creating complex animations for web and mobile platforms.

Lottie.js works by importing JSON files from Adobe After Effects that contain all of the animation data and assets required to create the animation. This makes it simple for designers and animators to use After Effects to create complex animations that can then be exported for use in web and mobile applications.
One of the main advantages of Lottie.js is its lightweight and fast nature, which allows for smooth and seamless animations even on low-powered devices. Lottie.js employs SVG, a vector-based and scalable format that ensures the animations look great on any device.
Lottie.js is also highly customizable, with a plethora of options for controlling the animation’s speed, direction, and other aspects. Developers can also make the animations interactive, allowing users to interact with them in a variety of ways.
Another significant advantage of Lottie.js is its cross-platform compatibility. Lottie animations can be used on a variety of platforms, including web, mobile (iOS and Android), and desktop (Windows and macOS). This makes it an excellent choice for developers who want to create animations that work across multiple platforms.
Lottie.js is also simple to use, with a simple API that makes it simple to add animations to web and mobile applications. Developers can simply include the Lottie.js library in their project and then load the JSON file containing the animation data.
Finally, Lottie.js has a large and active community of developers and designers who are constantly creating new animations and resources. This means that developers can easily find pre-built animations and resources to use in their projects, saving them time and effort.
To summarise, Lottie.js is a powerful and versatile JavaScript library that allows developers to easily create and use high-quality animations in web, mobile, and desktop applications. Its lightweight and customizable nature, cross-platform compatibility, ease of use, and active community make it an excellent choice for developers looking to create engaging and dynamic animations for their applications.