Window.sessionStorage

The read-only sessionStorage property accesses a session Storage object for the current origin. sessionStorage is similar to localStorage; the difference is that while data in localStorage doesn't expire, data in sessionStorage is cleared when the page session ends.

  • A page session lasts as long as the browser is open, and survives over page reloads and restores.
  • Opening a page in a new tab or window creates a new session with the value of the top-level browsing context, which differs from how session cookies work.
  • Opening multiple tabs/windows with the same URL creates sessionStorage for each tab/window.
  • Closing a tab/window ends the session and clears objects in sessionStorage.

Data stored in sessionStorage is specific to the protocol of the page. In particular, data stored by a script on a site accessed with HTTP (e.g., http://example.com) is put in a different sessionStorage object from the same site accessed with HTTPS (e.g., https://example.com).

The keys and the values are always in the UTF-16 DOMString format, which uses two bytes per character. As with objects, integer keys are automatically converted to strings.

Syntax

myStorage = window.sessionStorage;

Value

A Storage object which can be used to access the current origin's session storage space.

Exceptions

SecurityError
The request violates a policy decision, or the origin is not a valid scheme/host/port tuple (this can happen if the origin uses the file: or data: scheme, for example). For example, the user may have their browser configured to deny permission to persist data for the specified origin.

Examples

Basic usage

// Save data to sessionStorage
sessionStorage.setItem('key', 'value');

// Get saved data from sessionStorage
let data = sessionStorage.getItem('key');

// Remove saved data from sessionStorage
sessionStorage.removeItem('key');

// Remove all saved data from sessionStorage
sessionStorage.clear();

Saving text between refreshes

The following example autosaves the contents of a text field, and if the browser is refreshed, restores the text field content so that no writing is lost.

// Get the text field that we're going to track
let field = document.getElementById("field");
 
// See if we have an autosave value
// (this will only happen if the page is accidentally refreshed)
if (sessionStorage.getItem("autosave")) {
  // Restore the contents of the text field
  field.value = sessionStorage.getItem("autosave");
}
 
// Listen for changes in the text field
field.addEventListener("change", function() {
  // And save the results into the session storage object
  sessionStorage.setItem("autosave", field.value);
});

Note: Please refer to the Using the Web Storage API article for a full example.

Specifications

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

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
sessionStorageChrome Full support 5Edge Full support 12Firefox Full support 2IE Full support 8Opera Full support 10.5Safari Full support 4WebView Android Full support ≤37Chrome Android Full support 18Firefox Android Full support 4Opera Android Full support 11Safari iOS Full support 3.2Samsung Internet Android Full support 1.0

Legend

Full support  
Full support

See also