index.md

---

title: runtime.OnInstalledReason
slug: Mozilla/Add-ons/WebExtensions/API/runtime/OnInstalledReason
page-type: webextension-api-type
tags:
  - API
  - Add-ons
  - Extensions
  - Non-standard
  - OnInstalledReason
  - Reference
  - Type
  - WebExtensions
  - runtime
browser-compat: webextensions.api.runtime.OnInstalledReason

---

{{AddonSidebar()}}

The reason that the {{WebExtAPIRef("runtime.onInstalled")}} event is being dispatched.

Type

Values of this type are strings. Possible values are:

• "install"

  • : The extension was installed.

• "update"

  • : The extension was updated to a new version.

• "browser_update" or, for Chrome, "chrome_update"

  • : The browser was updated to a new version.

• "shared_module_update"

  • : Another extension, which contains a module used by this extension, was updated.

Browser compatibility

{{Compat}}

{{WebExtExamples}}

Note: This API is based on Chromium's chrome.runtime API. This documentation is derived from runtime.json in the Chromium code.