Window.sessionStorage

The sessionStorage property allows you to access a session Storage object for the current origin. sessionStorage is similar to Window.localStorage, the only difference is while data stored in localStorage has no expiration set, data stored in sessionStorage gets cleared when the page session ends. A page session lasts for as long as the browser is open and survives over page reloads and restores. Opening a page in a new tab or window will cause a new session to be initiated, which differs from how session cookies work.

It should be noted that data stored in either sessionStorage or localStorage is specific to the protocol of the page.

Syntax

// Save data to sessionStorage
sessionStorage.setItem('key', 'value');
// Get saved data from sessionStorage
var data = sessionStorage.getItem('key');
// Remove saved data from sessionStorage
sessionStorage.removeItem('key');
// Remove all saved data from sessionStorage
sessionStorage.clear();

Value

A Storage object.

Example

The following snippet accesses the current domain's session Storage object and adds a data item to it using Storage.setItem().

sessionStorage.setItem('myCat', 'Tom');

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

// Get the text field that we're going to track
var 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);
});

Specifications

Browser compatibility

All browsers have varying capacity levels for both localStorage and sessionStorage. Here is a detailed rundown of all the storage capacities for various browsers.

See also

• Using the Web Storage API
• Window.localStorage