The setItem() method of the Storage interface, when passed a key name and value, will add that key to the storage, or update that key's value if it already exists.

Syntax

storage.setItem(keyName, keyValue);

Parameters

keyName
A DOMString containing the name of the key you want to create/update.
keyValue
A DOMString containing the value you want to give the key you are creating/updating.

Return value

undefined.

Exceptions

setItem() may throw an exception if the storage is full. Particularly, in Mobile Safari (since iOS 5) it always throws when the user enters private mode (Safari sets quota to 0 bytes in private mode, contrary to other browsers, who allow storage in private mode, using separate data containers). Hence developers should make sure to always catch the possible exceptions from setItem().

Example

The following function creates three data items inside local storage.

function populateStorage() {
  localStorage.setItem('bgcolor', 'red');
  localStorage.setItem('font', 'Helvetica');
  localStorage.setItem('image', 'myCat.png');
}

Note: To see this used within a real world example, see our Web Storage Demo.

Specifications

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

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support 4Edge Full support 12Firefox Full support 3.5IE Full support 8Opera Full support 10.5Safari Full support 4WebView Android Full support YesChrome Android Full support 18Edge Mobile Full support 13Firefox Android Full support 6Opera Android Full support 11Safari iOS Full support 3.2Samsung Internet Android ?

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown

See also

Document Tags and Contributors

Last updated by: Sheppy,