JavaScript engine

JavaScript engines are interpreters that parse and execute JavaScript code. Modern JavaScript engines use just-in-time (JIT) compilation to convert JavaScript code into machine code that can be executed by a computer's processor. A JavaScript engine is typically developed and used in web browsers to run client-side code but can also be used in server-side environments like Node.js.

In a browser, the JavaScript engine operates together with the rendering engine via the Document Object Model and Web IDL bindings. Some JavaScript engines also execute WebAssembly code in the same sandbox as regular JavaScript code.

Do not confuse JavaScript engines with rendering engines, which are also crucial parts of browsers.

See also