The key() method of the Storage interface, when passed a number n, returns the name of the nth key in a given Storage object. The order of keys is user-agent defined, so you should not rely on it.


var aKeyName = storage.key(index);


An integer representing the number of the key you want to get the name of. This is a zero-based index.

Return value

A DOMString containing the name of the key. If the index does not exist, null is returned.


The following function iterates over the local storage keys:

function forEachKey(callback) {
  for (var i = 0; i < localStorage.length; i++) {

The following function iterates over the local storage keys and gets the value set for each key:

for(var i =0; i < localStorage.length; i++){

Note: For a real world example, see our Web Storage Demo.


Specification Status Comment
HTML Living Standard
The definition of 'Storage.key' in that specification.
Living Standard  

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
keyChrome Full support 4Edge Full support 12Firefox Full support 3.5IE Full support 8Opera Full support 10.5Safari Full support 4WebView Android Full support YesChrome Android Full support 18Firefox Android Full support 6Opera Android Full support 11Safari iOS Full support 3.2Samsung Internet Android Full support 1.0


Full support  
Full support

See also