Session object represents a tab or window that the user has closed in the current browsing session.
Sessions are represented as
Tab objects if the tab was closed but its window was not closed: for example, because the user clicked the "Close tab" button, and this tab was not the only tab in its window.
Sessions are represented as
Window objects if the window was closed: for example, because the user clicked the "Close window" button, or closed the only tab open in a window.
Note that different browsers might have a different idea of when a session is a Tab and when it is a Window. For example:
- In Chrome a session is recorded as a Window if the user closes a window that contained more than one tab. If the user closed a window that contained only one tab, this is recorded as a Tab.
- In Firefox, a session is recorded as a Window if the user closes a window (or a tab that was the last tab in the window), and a Tab if the user closes a tab that wasn't the last tab in its window.
Values of this type are objects. They contain the following properties:
number. The time the tab or window was closed, in milliseconds since the epoch.
object. If the object represents a closed tab, then this property is present and will be a
tabs.Tabobject. This will contain
favIconUrlonly if the add-on has the "tabs" permission.
object. If the object represents a closed window, then this property is present and will be a
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
|Chrome||Edge||Firefox||Firefox for Android||Opera|
|Basic support||Yes||No||52 1||No||Yes|
This API is based on Chromium's
Microsoft Edge compatibility data is supplied by Microsoft Corporation and is included here under the Creative Commons Attribution 3.0 United States License.
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