A
WebAssembly.Module object contains stateless WebAssembly code that has already been compiled by the browser and can be efficiently shared with Workers, cached in IndexedDB and instantiated multiple times.The
WebAssembly.Module() constructor function can be called to synchronously compile given WebAssembly binary code. However, the primary way to get a Module is through an asynchronous compilation function like WebAssembly.compile() or by reading a Module out of IndexedDB.Constructor Syntax
Important: Since compilation for large modules can be expensive, developers should only use the Module() constructor when synchronous compilation is absolutely required; the asynchronous WebAssembly.compileStreaming() method should be used at all other times.
var myModule = new WebAssembly.Module(bufferSource);
Parameters
- bufferSource
- A typed array or ArrayBuffer containing the binary code of the .wasm module you want to compile.
Function Properties of the Module Constructor
WebAssembly.Module.customSections()- Given a
Moduleand string, returns a copy of the contents of all custom sections in the module with the given string name. WebAssembly.Module.exports()- Given a
Module, returns an array containing descriptions of all the declared exports. WebAssembly.Module.imports()- Given a
Module, returns an array containing descriptions of all the declared imports.
Module instances
All Module instances inherit from the Module() constructor's prototype object — this can be modified to affect all Module instances.
Instance properties
Module.prototype.constructor- Returns the function that created this object's instance. By default this is the
WebAssembly.Module()constructor. Module.prototype[@@toStringTag]- The initial value of the @@toStringTag property is the String value "WebAssembly.Module".
Instance methods
Module instances have no default methods of their own.
Specifications
| Specification | Status | Comment |
|---|---|---|
| WebAssembly JavaScript Interface The definition of 'WebAssembly.Module()' in that specification. |
Working Draft | Initial draft definition. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
| Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic support | 57 | 16 | 522 | No | 44 | 11 |
customSections | 57 | 16 | 522 | No | 44 | 11 |
exports | 57 | 16 | 522 | No | 44 | 11 |
imports | 57 | 16 | 522 | No | 44 | 11 |
prototype | 57 | 16 | 522 | No | 44 | 11 |
| Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | Opera Android | iOS Safari | Samsung Internet |
|---|---|---|---|---|---|---|---|
| Basic support | 57 | 57 | Yes1 | 522 | ? | 11 | 7.0 |
customSections | 57 | 57 | Yes1 | 522 | ? | 11 | 7.0 |
exports | 57 | 57 | Yes1 | 522 | ? | 11 | 7.0 |
imports | 57 | 57 | Yes1 | 522 | ? | 11 | 7.0 |
prototype | 57 | 57 | Yes1 | 522 | ? | 11 | 7.0 |
1. This feature is behind the Experimental JavaScript Features preference.
2. Disabled in the Firefox 52 Extended Support Release (ESR).