内容表

• 方法
• 浏览器兼容性

storage.local

Represents the local storage area. Items in local storage are local to the machine the extension was installed on.

The browser may restrict the amount of data that an extension can store in the local storage area:

• Chrome limits the extension to 5MB of data using this API unless it has the "unlimitedStorage" permission .
• Firefox enables you to ask for the  "unlimitedStorage" permission from version 56 onwards. It does not yet restrict the amount of data your extension can store, but will start doing so in a future release. Thus, it's a good idea to ask for the "unlimitedStorage" permission now, if you intend to store a large amount of data.

When the extension is uninstalled, its associated local storage is cleared.

Also in Firefox, you can prevent the browser from clearing local storage on uninstall by visiting about:config  and setting the following two browser preferences to true : "keepUuidOnUninstall" and "keepStorageOnUninstall" . This feature is provided to help developers test their extensions. Extensions themselves are not able to change these preferences.

Although this API is similar to  Window.localStorage it is recommended that you don't use Window.localStorage in extension code. Firefox will clear data stored by extensions using the localStorage API in various scenarios where users clear their browsing history and data for privacy reasons, while data saved using the storage.local API will be correctly persisted in these scenarios.

方法

local object implements the methods defined on the storage.StorageArea 类型：

storage.StorageArea.get()

Retrieves one or more items from the storage area.

storage.StorageArea.getBytesInUse()

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

storage.StorageArea.set()

Stores one or more items in the storage area. If the item already exists, its value will be updated. When you set a value, the storage.onChanged event will fire.

storage.StorageArea.remove()

Removes one or more items from the storage area.

storage.StorageArea.clear()

Removes all items from the storage area.

浏览器兼容性

BCD tables only load in the browser

Example extensions

• annotate-page
• forget-it
• navigation-stats
• proxy-blocker
• quicknote
• stored-credentials

注意： This API is based on Chromium's chrome.storage 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.

Found a problem with this page?

• Edit on GitHub
• Source on GitHub
• Report a problem with this content on GitHub
• Want to fix the problem yourself? See our Contribution guide .

最后修改： Oct 26, 2021 , 由 MDN 贡献者

相关话题

1. 浏览器扩展名
2. 快速入门

   1. What are extensions?
   2. Your first extension
   3. Your second extension
   4. Anatomy of an extension
   5. Example extensions
   6. What next?
3. 概念

   1. Using the JavaScript APIs
   2. Content scripts
   3. Match patterns
   4. Working with files
   5. 国际化
   6. Content Security Policy
   7. Native messaging
   8. Differences between API implementations
   9. Chrome incompatibilities
4. 用户界面

   1. 用户界面
   2. Toolbar button
   3. Address bar button
   4. Sidebars
   5. Context menu items
   6. Options page
   7. Extension pages
   8. Notifications
   9. Address bar suggestions
   10. Developer tools panels
5. 如何

   1. Intercept HTTP requests
   2. Modify a web page
   3. Insert external content
   4. Share objects with page scripts
   5. Add a button to the toolbar
   6. Implement a settings page
   7. Work with the Tabs API
   8. Work with the Bookmarks API
   9. Work with the Cookies API
   10. Work with contextual identities
   11. Interact with the clipboard
   12. Build a cross-browser extension
6. Firefox differentiators
7. JavaScript API

   1. Browser support for JavaScript APIs
   2. alarms
   3. bookmarks
   4. browserAction
   5. browserSettings
   6. browsingData
   7. captivePortal
   8. clipboard
   9. 命令
   10. contentScripts
   11. contextualIdentities
   12. Cookie
   13. devtools
   14. dns
   15. downloads
   16. events
   17. extension
   18. extensionTypes
   19. find
   20. history
   21. i18n
   22. identity
   23. idle
   24. management
   25. menus
   26. notifications
   27. omnibox
   28. pageAction
   29. permissions
   30. pkcs11
   31. privacy
   32. proxy
   33. runtime
   34. search
   35. sessions
   36. sidebarAction
   37. storage
       1. 特性
          1. local
          2. managed
          3. sync
       2. 类型
          1. StorageArea
          2. StorageChange
       3. 事件
          1. onChanged
   38. tabs
   39. theme
   40. topSites
   41. 类型
   42. userScripts
   43. webNavigation
   44. webRequest
   45. windows
8. Manifest keys

   1. 介绍

   1. 作者
   2. background
   3. browser_action
   4. browser_specific_settings
   5. chrome_settings_overrides
   6. chrome_url_overrides
   7. 命令
   8. content_scripts
   9. content_security_policy
   10. default_locale
   11. description
   12. developer
   13. devtools_page
   14. dictionaries
   15. externally_connectable
   16. homepage_url
   17. icons
   18. incognito
   19. manifest_version
   20. name
   21. offline_enabled
   22. omnibox
   23. optional_permissions
   24. options_page
   25. options_ui
   26. page_action
   27. permissions
   28. protocol_handlers
   29. short_name
   30. sidebar_action
   31. storage
   32. theme
   33. theme_experiment
   34. user_scripts
   35. version
   36. version_name
   37. web_accessible_resources
9. Extension Workshop

   1. Develop
   2. Publish
   3. Manage
   4. Enterprise
10. Contact us
11. Channels

    1. Add-ons blog
    2. Add-ons forum
    3. Add-ons chat