The WebAssembly.compile() function compiles a WebAssembly.Module from WebAssembly binary code.  This function is useful if it is necessary to a compile a module before it can be instantiated (otherwise, the WebAssembly.instantiate() function should be used).


Promise<WebAssembly.Module> WebAssembly.compile(bufferSource);


A typed array or ArrayBuffer containing the binary code of the .wasm module you want to compile.

Return value

A Promise that resolves to a WebAssembly.Module object representing the compiled module.



The following example compiles the loaded simple.wasm byte code using the compile() function and then sends it to a worker using postMessage().

var worker = new Worker("wasm_worker.js");

fetch('simple.wasm').then(response =>
).then(bytes =>
).then(mod =>

Note: You'll probably want to use WebAssembly.compileStreaming() in most cases, as it is more efficient than compile().


Specification Status Comment
WebAssembly JavaScript Interface
The definition of 'compile()' in that specification.
Working Draft Initial draft definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support5716522 No4411
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support5757 Yes152244117.0

1. This feature is behind the Experimental JavaScript Features preference.

2. Disabled in the Firefox 52 Extended Support Release (ESR).

See also

Document Tags and Contributors

Contributors to this page: chrisdavidmills, fscholz, lukewagner
Last updated by: chrisdavidmills,