Alpine.js is a lightweight JavaScript framework for building interactive user interfaces. It is a collection of just 15 attributes, 6 properties, and 2 methods. It is suitable for developing small projects and prototypes. It is fashioned like a lightweight backpack with a minimalist API and thoughtful features.

Alpine.js is based on Vue.js, which makes it easier for Vue developers to use. It promises a blend of the reactive and declarative nature of frameworks such as Vue or React but at a lower cost in terms of learning curve or complexity.