Stores one or more items in the storage area, or update existing items.

When you store or update a value using this API, the storage.onChanged event will fire.

  keys,             // object
  function(){...}   // function

This API is also available as<storageType>.set() in a version that returns a promise.

<storageType> will be one of the writable storage types — storage.sync or storage.local.


An object containing one or more key/value pairs to be stored in storage. If an item already exists, its value will be updated.
  • Primitive values (such as numbers) and arrays will serialize as expected.
  • Functions will be omitted.
  • Dates, and Regexes will serialize using their String representation.
callback Optional
A callback function that is run when the operation completes. The callback takes no arguments. If the operation failed, runtime.lastError is set.

Browser compatibility

Chrome Edge Firefox Firefox for Android Opera
Basic support Yes Yes 45.0 48.0 33

Compatibility notes


  • storage is limited to 1MB per value.


// callback to set() just checks for errors
function onSet() {
  if (chrome.runtime.lastError) {
  } else {

// define 2 objects, that contain:
// a string, a function, a Date
var monster = {
  name: "Kraken",
  speak: function() {console.log("ROARR!!!")},
  birthday: new Date(2012, 11, 17)

var kitten = {
  name: "Moggy",
  speak: function() {console.log("Miaow")},
  birthday: new Date(2006, 7, 12)

// store the objects{kitten, monster}, onSet);

function gotItem(item) {
  if (chrome.runtime.lastError) {
  } else {
}"kitten", gotItem);
// the function is omitted
// the Date is stored as a string
// -> {birthday: "2006-08-12T07:00:00.000Z", name: "Moggy"}

Example add-ons


This API is based on Chromium's API. This documentation is derived from storage.json in the Chromium code.

Microsoft Edge compatibility data is supplied by Microsoft Corporation and is included here under the Creative Commons Attribution 3.0 United States License.

Document Tags and Contributors

 Contributors to this page: Makyen, wbamberg, chrisdavidmills
 Last updated by: Makyen,