Storage: key() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

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

js
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 string 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:

js
function forEachKey(callback) {
  for (let 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:

js
for (let i = 0; i < localStorage.length; i++) {
  console.log(localStorage.getItem(localStorage.key(i)));
}

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

Specifications

Specification
HTML Standard
# dom-storage-key-dev

Browser compatibility

BCD tables only load in the browser

See also