The Window.crypto read-only property returns the Crypto object associated to the global object. This object allows web pages access to certain cryptographic related services.


var cryptoObj = window.crypto || window.msCrypto; // for IE 11


Using the Window.crypto property to access the getRandomValues() method.


genRandomNumbers = function getRandomNumbers() {
  var array = new Uint32Array(10);
  var randText = document.getElementById("myRandText");
  randText.innerHTML = "The random numbers are: "
  for (var i = 0; i < array.length; i++) {
    randText.innerHTML += array[i] + " ";


<p id="myRandText">The random numbers are: </p>
<button type="button" onClick='genRandomNumbers()'>Generate 10 random numbers</button>



Specification Status Comment
Web Cryptography API
The definition of 'Window.crypto' in that specification.
Recommendation Initial definition

Browser compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Edge Firefox (Gecko) Internet Explorer Edge Opera Safari
Basic support 44 (Yes) (Yes) (Yes) 11 ms 20 19 (Yes)
Feature Chrome for Android Edge Firefox Mobile Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

See also

Document Tags and Contributors

Last updated by: joshuaptfan,