The storage area's access level.

Enum

Properties

• onChanged

  Event<functionvoidvoid>

  Chrome 73+

  Fired when one or more items change.

  TheonChanged.addListener function looks like:

  (callback: function) => {...}

  • callback

    function

    Thecallback parameter looks like:

    (changes: object) => void

    • changes

      object

• clear

  void

  Promise

  Removes all items from storage.

  Theclear function looks like:

  (callback?: function) => {...}

  • callback

    function optional

    Thecallback parameter looks like:

    () => void

  • returns

    Promise<void>

    Chrome 95+

    Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

• get

  void

  Promise

  Gets one or more items from storage.

  Theget function looks like:

  (keys?: string | string[] | object, callback?: function) => {...}

  • keys

    string | string[] | object optional

    A single key to get, list of keys to get, or a dictionary specifying default values (see description of the object). An empty list or object will return an empty result object. Pass innull to get the entire contents of storage.

  • callback

    function optional

    Thecallback parameter looks like:

    (items: object) => void

    • items

      object

      Object with items in their key-value mappings.

  • returns

    Promise<object>

    Chrome 95+

    Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

• getBytesInUse

  void

  Promise

  Gets the amount of space (in bytes) being used by one or more items.

  ThegetBytesInUse function looks like:

  (keys?: string | string[], callback?: function) => {...}

  • keys

    string | string[] optional

    A single key or list of keys to get the total usage for. An empty list will return 0. Pass innull to get the total usage of all of storage.

  • callback

    function optional

    Thecallback parameter looks like:

    (bytesInUse: number) => void

    • bytesInUse

      number

      Amount of space being used in storage, in bytes.

  • returns

    Promise<number>

    Chrome 95+

    Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

• getKeys

  void

  PromiseChrome 130+

  Gets all keys from storage.

  ThegetKeys function looks like:

  (callback?: function) => {...}

  • callback

    function optional

    Thecallback parameter looks like:

    (keys: string[]) => void

    • keys

      string[]

      Array with keys read from storage.

  • returns

    Promise<string[]>

    Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

• remove

  void

  Promise

  Removes one or more items from storage.

  Theremove function looks like:

  (keys: string | string[], callback?: function) => {...}

  • keys

    string | string[]

    A single key or a list of keys for items to remove.

  • callback

    function optional

    Thecallback parameter looks like:

    () => void

  • returns

    Promise<void>

    Chrome 95+

    Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

• set

  void

  Promise

  Sets multiple items.

  Theset function looks like:

  (items: object, callback?: function) => {...}

  • items

    object

    An object which gives each key/value pair to update storage with. Any other key/value pairs in storage will not be affected.

    Primitive values such as numbers will serialize as expected. Values with atypeof"object" and"function" will typically serialize to{}, with the exception ofArray (serializes as expected),Date, andRegex (serialize using theirString representation).

  • callback

    function optional

    Thecallback parameter looks like:

    () => void

  • returns

    Promise<void>

    Chrome 95+

    Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

• setAccessLevel

  void

  PromiseChrome 102+

  Sets the desired access level for the storage area. By default,session storage is restricted to trusted contexts (extension pages and service workers), whilelocal andsync storage allow access from both trusted and untrusted contexts.

  ThesetAccessLevel function looks like:

  (accessOptions: object, callback?: function) => {...}

  • accessOptions

    object

    • accessLevel

      AccessLevel

      The access level of the storage area.

  • callback

    function optional

    Thecallback parameter looks like:

    () => void

  • returns

    Promise<void>

    Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

Properties

• 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.

Items in thelocal storage area are local to each machine.

Type

Properties

• QUOTA_BYTES

  10485760
  

  The maximum amount (in bytes) of data that can be stored in local storage, as measured by the JSON stringification of every value plus every key's length. This value will be ignored if the extension has theunlimitedStorage permission. Updates that would cause this limit to be exceeded fail immediately and setruntime.lastError when using a callback, or a rejected Promise if using async/await.

Items in themanaged storage area are set by an enterprise policy configured by the domain administrator, and are read-only for the extension; trying to modify this namespace results in an error. For information on configuring a policy, seeManifest for storage areas.

Type

Items in thesession storage area are stored in-memory and will not be persisted to disk.

Type

Properties

• QUOTA_BYTES

  10485760
  

  The maximum amount (in bytes) of data that can be stored in memory, as measured by estimating the dynamically allocated memory usage of every value and key. Updates that would cause this limit to be exceeded fail immediately and setruntime.lastError when using a callback, or when a Promise is rejected.

Items in thesync storage area are synced using Chrome Sync.

Type

Properties

• MAX_ITEMS

  512
  

  The maximum number of items that can be stored in sync storage. Updates that would cause this limit to be exceeded will fail immediately and setruntime.lastError when using a callback, or when a Promise is rejected.

• MAX_SUSTAINED_WRITE_OPERATIONS_PER_MINUTE

  1000000
  

  Deprecated

  The storage.sync API no longer has a sustained write operation quota.

• MAX_WRITE_OPERATIONS_PER_HOUR

  1800
  

  The maximum number ofset,remove, orclear operations that can be performed each hour. This is 1 every 2 seconds, a lower ceiling than the short term higher writes-per-minute limit.

  Updates that would cause this limit to be exceeded fail immediately and setruntime.lastError when using a callback, or when a Promise is rejected.

• MAX_WRITE_OPERATIONS_PER_MINUTE

  120
  

  The maximum number ofset,remove, orclear operations that can be performed each minute. This is 2 per second, providing higher throughput than writes-per-hour over a shorter period of time.

  Updates that would cause this limit to be exceeded fail immediately and setruntime.lastError when using a callback, or when a Promise is rejected.

• QUOTA_BYTES

  102400
  

  The maximum total amount (in bytes) of data that can be stored in sync storage, as measured by the JSON stringification of every value plus every key's length. Updates that would cause this limit to be exceeded fail immediately and setruntime.lastError when using a callback, or when a Promise is rejected.

• QUOTA_BYTES_PER_ITEM

  8192
  

  The maximum size (in bytes) of each individual item in sync storage, as measured by the JSON stringification of its value plus its key length. Updates containing items larger than this limit will fail immediately and setruntime.lastError when using a callback, or when a Promise is rejected.

chrome.storage.onChanged.addListener(
  callback: function,
)

Fired when one or more items change.

Parameters

• callback

  function

  Thecallback parameter looks like:

  (changes: object, areaName: string) => void

  • changes

    object

  • areaName

    string