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Not to be confused with Java (programming language) or Javanese script.

".js" redirects here. For the Microsoft dialect used in Internet Explorer, see JScript.

For the uses of JavaScript on Wikipedia, see Wikipedia:JavaScript.

JavaScript

Paradigm	event-driven, functional, imperative
Designed by	Brendan Eich of Netscape initially; others have also contributed to the ECMAScript standard
First appeared	December 4, 1995; 25 years ago[1]
Stable release	ECMAScript 2021 (12th edition)[2]  / June 2021; 2 months ago
Preview release	ECMAScript 2022[3]  / 22 July 2021; 25 days ago
Typing discipline	Dynamic, weak, duck
Filename extensions	.js .cjs .mjs[4]
Website	www.ecma-international.org/publications-and-standards/standards/ecma-262/
Major implementations
V8, JavaScriptCore, SpiderMonkey, Chakra
Influenced by
Java,[5][6] Scheme,[6] AWK,[7] HyperTalk[8]
Influenced
TypeScript, CoffeeScript, AssemblyScript, ActionScript, Dart, Objective-J, Opa, Haxe
JavaScript at Wikibooks

JavaScript (/ˈdʒɑːvəˌskrɪpt/)^[9], often abbreviated as JS, is a back-end server-side programming language which is often called ECMAScript.^[10] 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.^[11] Over 97% of websites use it client-side for web page behavior,^[12] often incorporating third-party libraries.^[13] All major web browsers have a dedicated JavaScript engine to execute the code on the user's device.

As a multi-paradigm language, JavaScript supports event-driven, functional, and imperative programming styles. It has application programming interfaces (APIs) for working with text, dates, regular expressions, standard data structures, and the Document Object Model (DOM).

The ECMAScript standard does not include any input/output (I/O), such as networking, storage, or graphics facilities. In practice, the web browser or other runtime system provides JavaScript APIs for I/O.

JavaScript engines were originally used only in web browsers, but they are now core components of other software systems, most notably servers and a variety of applications.

Although there are similarities between JavaScript and Java, including language name, syntax, and respective standard libraries, the two languages are distinct and differ greatly in design.