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This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

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
Web Assembly JavaScript API
The definition of 'WebAssembly.Module()' in that specification.
Draft Initial draft definition.

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 57 No support 52 (52) No support (Yes) No support
Feature Chrome for Android Android Webview Edge Mobile Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support 57 57 No support 52.0 (52) No support No support No support

See also

Document Tags and Contributors

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