This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The WebAssembly.Instance.prototype property represents the prototype for the WebAssembly.Instance() constructor.

Property attributes of WebAssembly.Instance.prototype
Writable no
Enumerable no
Configurable no


All WebAssembly.Instance instances inherit from Instance.prototype. The prototype object of the WebAssembly.Instance() constructor can be modified to affect all WebAssembly.Instance instances.


Returns the function that created this object's instance. By default this is the WebAssembly.Instance() constructor.
Instance.prototype.exports Read only
Returns an object containing as its members all the functions exported from the WebAssembly module instance, to allow them to be accessed and used by JavaScript.




Specification Status Comment
WebAssembly JavaScript Interface
The definition of 'WebAssembly.Module()' 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 Yes1522 ?117.0

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: fscholz, chrisdavidmills
Last updated by: fscholz,