storage API

Use the browser.storage API to store, retrieve, and track changes to user data.

Note

The permission storage is required to use messenger.storage.*.

Events

onChanged

Fired when one or more items change.

Parameters for onChanged.addListener(listener)

listener(changes, areaName)

A function that will be called when this event occurs.

Parameters passed to the listener function

changes

(object)

Object mapping each key that changed to its corresponding StorageChange for that item.

areaName

(string)

The name of the storage area (“sync”, “local” or “managed”) the changes are for.

Required permissions

storage

Types

StorageArea

object

clear([callback]) Removes all items from storage.
get([keys], callback) Gets one or more items from storage.
getBytesInUse([keys], callback) Gets the amount of space (in bytes) being used by one or more items.
remove(keys, [callback]) Removes one or more items from storage.
set(items, [callback]) Sets multiple items.

StorageAreaSync

object

clear([callback]) Removes all items from storage.
get([keys], callback) Gets one or more items from storage.
getBytesInUse([keys], callback) Gets the amount of space (in bytes) being used by one or more items.
remove(keys, [callback]) Removes one or more items from storage.
set(items, [callback]) Sets multiple items.

StorageChange

object

[newValue]

(any, optional)

The new value of the item, if there is a new value.

[oldValue]

(any, optional)

The old value of the item, if there was an old value.

Properties

local

Items in the local storage area are local to each machine.

managed

Items in the managed storage area are set by administrators or native applications, and are read-only for the extension; trying to modify this namespace results in an error.

session

Items in the session storage area are kept in memory, and only until the either browser or extension is closed or reloaded.

sync

Items in the sync storage area are synced by the browser.