Web/API/Storage/key

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.

Syntax

var aKeyName = storage.key(index);

Parameters

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.

Examples

The following function iterates over the local storage keys:

function forEachKey(callback) {
  for (var i = 0; i < localStorage.length; i++) {
    callback(localStorage.key(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++){
  console.log(localStorage.getItem(localStorage.key(i)));
}

Note: For a real world example, see our [[../../../../../../../mdn.github.io/dom-examples/web-storage/index|Web Storage Demo]].

Specifications

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

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`key`	Chrome Full support 4	Edge Full support 12	Firefox Full support 3.5	IE Full support 8	Opera Full support 10.5	Safari Full support 4	WebView Android Full support Yes	Chrome Android Full support 18	Firefox Android Full support 6	Opera Android Full support 11	Safari iOS Full support 3.2	Samsung Internet Android Full support 1.0

Legend

Full support: Full support