Storage: length property

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 length read-only property of the Storage interface returns the number of data items stored in a given Storage object.

Value

The number of items stored in the Storage object.

Examples

The following function adds three data items to the local storage for the current domain, then returns the number of items in the storage:

js
function populateStorage() {
  localStorage.setItem("bgcolor", "yellow");
  localStorage.setItem("font", "Helvetica");
  localStorage.setItem("image", "cats.png");

  return localStorage.length; // Should return 3
}

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

Specifications

Specification
HTML
# dom-storage-length-dev

Browser compatibility

desktop mobile server
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
length
Chrome – Full support
Chrome 4 (Release date: 2010-01-25)
footnote Full support
Edge – Full support
Edge 12 (Release date: 2015-07-29)
footnote Full support
Firefox – Full support
Firefox 3.5 (Release date: 2009-06-30)
footnote Full support
Opera – Full support
Opera 10.5 (Release date: 2010-03-02)
footnote Full support
Safari – Full support
Safari 4 (Release date: 2009-06-08)
footnote Full support
Chrome Android – Full support
Chrome Android 18 (Release date: 2012-06-27)
footnote Full support
Firefox for Android – Full support
Firefox for Android 6 (Release date: 2011-08-16)
footnote Full support
Opera Android – Full support
Opera Android 11 (Release date: 2011-03-22)
footnote Full support
Safari on iOS – Full support
Safari on iOS 3.2 (Release date: 2010-04-03)
footnote Full support
Samsung Internet – Full support
Samsung Internet 1 (Release date: 2013-04-27)
footnote Full support
WebView Android – Full support
WebView Android 4.4 (Release date: 2013-12-09)
footnote Full support
WebView on iOS – Full support
WebView on iOS 3.2 (Release date: 2010-04-03)
footnote Full support
Deno – Full support
Deno 1.10 (Release date: 2021-05-11)
footnote Full support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also