browser.tabs

Description

The Tabs API not only offers features for manipulating and managing tabs, but can also detect the language of the tab, take a screenshot, and communicate with a tab's content scripts.

Permissions

Most features don't require any permissions to use. For example: creating a new tab, reloading a tab, navigating to another URL, etc.

There are three permissions developers should be aware of when working with the Tabs API.

The "tabs" permission

This permission does not give access to the browser.tabs namespace. Instead, it grants an extension the ability to call tabs.query() against four sensitive properties on tabs.Tab instances: url, pendingUrl, title, and favIconUrl.

{
  "name": "My extension",
  ...
  "permissions": [
    "tabs"
  ],
  ...
}

Host permissions

Host permissions allow an extension to read and query a matching tab's four sensitive tabs.Tab properties. They can also interact directly with the matching tabs using methods such as tabs.captureVisibleTab(), scripting.executeScript(), scripting.insertCSS(), and scripting.removeCSS().

{
  "name": "My extension",
  ...
  "host_permissions": [
    "http://*/*",
    "https://*/*"
  ],
  ...
}

The "activeTab" permission

activeTab grants an extension temporary host permission for the current tab in response to a user invocation. Unlike host permissions, activeTab does not trigger any warnings.

{
  "name": "My extension",
  ...
  "permissions": [
    "activeTab"
  ],
  ...
}

Use cases

The following sections demonstrate some common use cases.

Open an extension page in a new tab

A common pattern for extensions is to open an onboarding page in a new tab when the extension is installed. The following example shows how to do this.

background.js: