JavaScript (/ˈdʒɑːvəˌskrɪpt/), ^[6] often abbreviated as JS, is a programming language that conforms to the ECMAScript specification.^[7] JavaScript is high-level, often just-in-time compiled, and multi-paradigm. It has curly-bracket syntax, dynamic typing, prototype-based object-orientation, and first-class functions.

Alongside HTML and CSS, JavaScript is one of the core technologies of the World Wide Web.^[8] JavaScript enables interactive web pages and is an essential part of web applications. The vast majority of websites use it for client-side page behavior,^[9] and all major web browsers have a dedicated JavaScript engine to execute it.