Web/API/Storage

From Get docs


The Storage interface of the Web Storage API provides access to a particular domain's session or local storage. It allows, for example, the addition, modification, or deletion of stored data items.

To manipulate, for instance, the session storage for a domain, a call to Window.sessionStorage is made; whereas for local storage the call is made to Window.localStorage.

Properties

Storage.length Read only
Returns an integer representing the number of data items stored in the Storage object.

Methods

Storage.key()
When passed a number n, this method will return the name of the nth key in the storage.
Storage.getItem()
When passed a key name, will return that key's value.
Storage.setItem()
When passed a key name and value, will add that key to the storage, or update that key's value if it already exists.
Storage.removeItem()
When passed a key name, will remove that key from the storage.
Storage.clear()
When invoked, will empty all keys out of the storage.

Examples

Here we access a Storage object by calling localStorage. We first test whether the local storage contains data items using !localStorage.getItem('bgcolor'). If it does, we run a function called setStyles() that grabs the data items using Storage.getItem() and uses those values to update page styles. If it doesn't, we run another function, populateStorage(), which uses Storage.setItem() to set the item values, then runs setStyles().

if(!localStorage.getItem('bgcolor')) {
  populateStorage();
} else {
  setStyles();
}

function populateStorage() {
  localStorage.setItem('bgcolor', document.getElementById('bgcolor').value);
  localStorage.setItem('font', document.getElementById('font').value);
  localStorage.setItem('image', document.getElementById('image').value);

  setStyles();
}

function setStyles() {
  var currentColor = localStorage.getItem('bgcolor');
  var currentFont = localStorage.getItem('font');
  var currentImage = localStorage.getItem('image');

  document.getElementById('bgcolor').value = currentColor;
  document.getElementById('font').value = currentFont;
  document.getElementById('image').value = currentImage;

  htmlElem.style.backgroundColor = '#' + currentColor;
  pElem.style.fontFamily = currentFont;
  imgElem.setAttribute('src', currentImage);
}

Note: To see this running as a complete working example, see our [[../../../../../../mdn.github.io/dom-examples/web-storage/index|Web Storage Demo]].


Specifications

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

Browser compatibility

Update compatibility data on GitHub

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
Storage Chrome

Full support 4

Edge

Full support 12

Firefox

Full support 3.5

IE

Full support 8

Opera

Full support 10.5

Safari

Full support 4

WebView Android

Full support ≤37

Chrome Android

Full support 18

Firefox Android

Full support 6

Opera Android

Full support 11

Safari iOS

Full support 3.2

Samsung Internet Android

Full support 1.0

clear Chrome

Full support 4

Edge

Full support 12

Firefox

Full support 3.5

IE

Full support 8

Opera

Full support 10.5

Safari

Full support 4

WebView Android

Full support Yes

Chrome Android

Full support 18

Firefox Android

Full support 6

Opera Android

Full support 11

Safari iOS

Full support 3.2

Samsung Internet Android

Full support 1.0

getItem Chrome

Full support 4

Edge

Full support 12

Firefox

Full support 3.5

IE

Full support 8

Opera

Full support 10.5

Safari

Full support 4

WebView Android

Full support ≤37

Chrome Android

Full support 18

Firefox Android

Full support 6

Opera Android

Full support 11

Safari iOS

Full support 3.2

Samsung Internet Android

Full support 1.0

key Chrome

Full support 4

Edge

Full support 12

Firefox

Full support 3.5

IE

Full support 8

Opera

Full support 10.5

Safari

Full support 4

WebView Android

Full support Yes

Chrome Android

Full support 18

Firefox Android

Full support 6

Opera Android

Full support 11

Safari iOS

Full support 3.2

Samsung Internet Android

Full support 1.0

length Chrome

Full support 4

Edge

Full support 12

Firefox

Full support 3.5

IE

Full support 8

Opera

Full support 10.5

Safari

Full support 4

WebView Android

Full support Yes

Chrome Android

Full support 18

Firefox Android

Full support 6

Opera Android

Full support 11

Safari iOS

Full support 3.2

Samsung Internet Android

Full support 1.0

removeItem Chrome

Full support 4

Edge

Full support 12

Firefox

Full support 3.5

IE

Full support 8

Opera

Full support 10.5

Safari

Full support 4

WebView Android

Full support ≤37

Chrome Android

Full support 18

Firefox Android

Full support 6

Opera Android

Full support 11

Safari iOS

Full support 3.2

Samsung Internet Android

Full support 1.0

setItem Chrome

Full support 4

Edge

Full support 12

Firefox

Full support 3.5

IE

Full support 8

Opera

Full support 10.5

Safari

Full support 4

WebView Android

Full support ≤37

Chrome Android

Full support 18

Firefox Android

Full support 6

Opera Android

Full support 11

Safari iOS

Full support 3.2

Samsung Internet Android

Full support 1.0

Legend

Full support  
Full support


See also

Storage by Mozilla Contributors is licensed under CC-BY-SA 2.5.