--- title: WebAssembly slug: WebAssembly tags: - Landing - WebAssembly - wasm translation_of: WebAssembly ---
WebAssembly has huge implications for the web platform — it provides a way to run code written in multiple languages on the web at near native speed, with client apps running on the web that previously couldn’t have done so.
WebAssembly is designed to complement and run alongside JavaScript — using the WebAssembly JavaScript APIs, you can load WebAssembly modules into a JavaScript app and share functionality between the two. This allows you to take advantage of WebAssembly's performance and power and JavaScript's expressiveness and flexibility in the same apps, even if you don't know how to write WebAssembly code.
And what's even better is that it is being developed as a web standard via the W3C WebAssembly Working Group and Community Group with active participation from all major browser vendors.
WebAssembly.Global object represents a global variable instance, accessible from both JavaScript and importable/exportable across one or more {{jsxref("WebAssembly.Module")}} instances. This allows dynamic linking of multiple modules.WebAssembly.Module object contains stateless WebAssembly code that has already been compiled by the browser and can be efficiently shared with Workers, and instantiated multiple times.WebAssembly.Instance object is a stateful, executable instance of a Module. Instance objects contain all the Exported WebAssembly functions that allow calling into WebAssembly code from JavaScript.WebAssembly.instantiateStreaming() function is the primary API for compiling and instantiating WebAssembly code, returning both a Module and its first Instance.WebAssembly.Memory object is a resizable {{jsxref("Global_objects/ArrayBuffer", "ArrayBuffer")}} that holds the raw bytes of memory accessed by an Instance.WebAssembly.Table object is a resizable typed array of opaque values, like function references, that are accessed by an Instance.CompileError object.LinkError object.RuntimeError object.| Specification | Status | Comment |
|---|---|---|
| {{SpecName('WebAssembly JS')}} | {{Spec2('WebAssembly JS')}} | Initial draft definition of the JavaScript API. |
{{Compat("javascript.builtins.WebAssembly")}}