chrome.browserAction

Description

Use browser actions to put icons in the main Google Chrome toolbar, to the right of the address bar. In addition to its icon, a browser action can have a tooltip, a badge, and a popup.

Availability

≤ MV2

In the following figure, the multicolored square to the right of the address bar is the icon for a browser action. A popup is below the icon.

If you want to create an icon that isn't always active, use a page action instead of a browser action.

Manifest

Register your browser action in the extension manifest like this:

{
  "name": "My extension",
  ...
  "browser_action": {
    "default_icon": {                // optional
      "16": "images/icon16.png",     // optional
      "24": "images/icon24.png",     // optional
      "32": "images/icon32.png"      // optional
    },
    "default_title": "Google Mail",  // optional, shown in tooltip
    "default_popup": "popup.html"    // optional
  },
  ...
}

You can provide any size icon to be used in Chrome, and Chrome will select the closest one and scale it to the appropriate size to fill the 16-dip space. However, if the exact size isn't provided, this scaling can cause the icon to lose detail or look fuzzy.

Since devices with less-common scale factors like 1.5x or 1.2x are becoming more common, you are encouraged to provide multiple sizes for your icons. This also ensures that if the icon display size is ever changed, you don't need to do any more work to provide different icons!

The old syntax for registering the default icon is still supported:

{
  "name": "My extension",
  ...
  "browser_action": {
    ...
    "default_icon": "images/icon32.png"  // optional
    // equivalent to "default_icon": { "32": "images/icon32.png" }
  },
  ...
}

Parts of the UI

A browser action can have an icon, a tooltip, a badge, and a popup.

Icon

The browser action icons in Chrome are 16 dips (device-independent pixels) wide and high. Larger icons are resized to fit, but for best results, use a 16-dip square icon.

You can set the icon in two ways: using a static image or using the HTML5 canvas element. Using static images is easier for simple applications, but you can create more dynamic UIs—such as smooth animation—using the canvas element.

Static images can be in any format WebKit can display, including BMP, GIF, ICO, JPEG, or PNG. For unpacked extensions, images must be in the PNG format.

To set the icon, use the default_icon field of browser_action in the manifest, or call the browserAction.setIcon method.

To properly display icon when screen pixel density (ratio size_in_pixel / size_in_dip) is different than 1, the icon can be defined as set of images with different sizes. The actual image to display will be selected from the set to best fit the pixel size of 16 dip. The icon set can contain any size icon specification, and Chrome will select the most appropriate one.

Tooltip

To set the tooltip, use the default_title field of browser_action in the manifest, or call the browserAction.setTitle method. You can specify locale-specific strings for the default_title field; see Internationalization for details.

Badge

Browser actions can optionally display a badge—a bit of text that is layered over the icon. Badges make it easy to update the browser action to display a small amount of information about the state of the extension.

Because the badge has limited space, it should have 4 characters or less.

Set the text and color of the badge using browserAction.setBadgeText and browserAction.setBadgeBackgroundColor, respectively.

If a browser action has a popup, the popup appears when the user clicks the extension's icon. The popup can contain any HTML contents that you like, and it's automatically sized to fit its contents. The popup cannot be smaller than 25x25 and cannot be larger than 800x600.

To add a popup to your browser action, create an HTML file with the popup's contents. Specify the HTML file in the default_popup field of browser_action in the manifest, or call the browserAction.setPopup method.

Tips

For the best visual impact, follow these guidelines:

  • Do use browser actions for features that make sense on most pages.
  • Don't use browser actions for features that make sense for only a few pages. Use page actions instead.
  • Do use big, colorful icons that make the most of the 16x16-dip space. Browser action icons should seem a little bigger and heavier than page action icons.
  • Don't attempt to mimic Google Chrome's monochrome menu icon. That doesn't work well with themes, and anyway, extensions should stand out a little.
  • Do use alpha transparency to add soft edges to your icon. Because many people use themes, your icon should look nice on a variety of background colors.
  • Don't constantly animate your icon. That's just annoying.

Examples

You can find simple examples of using browser actions in the examples/api/browserAction directory. For other examples and for help in viewing the source code, see Samples.

Types

ColorArray

Type

[number, number, number, number]

ImageDataType

Pixel data for an image. Must be an ImageData object; for example, from a canvas element.

Type

ImageData

TabDetails

Chrome 88+

Properties

  • tabId

    number optional

    The ID of the tab to query state for. If no tab is specified, the non-tab-specific state is returned.

Methods

disable()

Promise 
chrome.browserAction.disable(
  tabId?: number,
  callback?: function,
)

Disables the browser action for a tab.

Parameters

  • tabId

    number optional

    The ID of the tab for which to modify the browser action.

  • callback

    function optional

    Chrome 67+

    The callback parameter looks like: 

    () => void

Returns

  • Promise<void>

    Chrome 88+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

enable()

Promise 
chrome.browserAction.enable(
  tabId?: number,
  callback?: function,
)

Enables the browser action for a tab. Defaults to enabled.

Parameters

  • tabId

    number optional

    The ID of the tab for which to modify the browser action.

  • callback

    function optional

    Chrome 67+

    The callback parameter looks like: 

    () => void

Returns

  • Promise<void>

    Chrome 88+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

getBadgeBackgroundColor()

Promise 
chrome.browserAction.getBadgeBackgroundColor(
  details: TabDetails,
  callback?: function,
)

Gets the background color of the browser action.

Parameters

Returns

  • Promise<ColorArray>

    Chrome 88+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

getBadgeText()

Promise 
chrome.browserAction.getBadgeText(
  details: TabDetails,
  callback?: function,
)

Gets the badge text of the browser action. If no tab is specified, the non-tab-specific badge text is returned.

Parameters

  • details

    TabDetails

  • callback

    function optional

    The callback parameter looks like: 

    (result: string) => void

    • result

      string

Returns

  • Promise<string>

    Chrome 88+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

getPopup()

Promise 
chrome.browserAction.getPopup(
  details: TabDetails,
  callback?: function,
)

Gets the HTML document that is set as the popup for this browser action.

Parameters

  • details

    TabDetails

  • callback

    function optional

    The callback parameter looks like: 

    (result: string) => void

    • result

      string

Returns

  • Promise<string>

    Chrome 88+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

getTitle()

Promise 
chrome.browserAction.getTitle(
  details: TabDetails,
  callback?: function,
)

Gets the title of the browser action.

Parameters

  • details

    TabDetails

  • callback

    function optional

    The callback parameter looks like: 

    (result: string) => void

    • result

      string

Returns

  • Promise<string>

    Chrome 88+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

setBadgeBackgroundColor()

Promise 
chrome.browserAction.setBadgeBackgroundColor(
  details: object,
  callback?: function,
)

Sets the background color for the badge.

Parameters

  • details

    object

    • color

      string | ColorArray

      An array of four integers in the range 0-255 that make up the RGBA color of the badge. Can also be a string with a CSS hex color value; for example, #FF0000 or #F00 (red). Renders colors at full opacity.

    • tabId

      number optional

      Limits the change to when a particular tab is selected. Automatically resets when the tab is closed.

  • callback

    function optional

    Chrome 67+

    The callback parameter looks like: 

    () => void

Returns

  • Promise<void>

    Chrome 88+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

setBadgeText()

Promise 
chrome.browserAction.setBadgeText(
  details: object,
  callback?: function,
)

Sets the badge text for the browser action. The badge is displayed on top of the icon.

Parameters

  • details

    object

    • tabId

      number optional

      Limits the change to when a particular tab is selected. Automatically resets when the tab is closed.

    • text

      string optional

      Any number of characters can be passed, but only about four can fit into the space. If an empty string ('') is passed, the badge text is cleared. If tabId is specified and text is null, the text for the specified tab is cleared and defaults to the global badge text.

  • callback

    function optional

    Chrome 67+

    The callback parameter looks like: 

    () => void

Returns

  • Promise<void>

    Chrome 88+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

setIcon()

Promise 
chrome.browserAction.setIcon(
  details: object,
  callback?: function,
)

Sets the icon for the browser action. The icon can be specified as the path to an image file, as the pixel data from a canvas element, or as a dictionary of one of those. Either the path or the imageData property must be specified.

Parameters

  • details

    object

    • imageData

      ImageData | object optional

      Either an ImageData object or a dictionary {size -> ImageData} representing an icon to be set. If the icon is specified as a dictionary, the image used is chosen depending on the screen's pixel density. If the number of image pixels that fit into one screen space unit equals scale, then an image with size scale * n is selected, where n is the size of the icon in the UI. At least one image must be specified. Note that 'details.imageData = foo' is equivalent to 'details.imageData = {'16': foo}'

    • path

      string | object optional

      Either a relative image path or a dictionary {size -> relative image path} pointing to an icon to be set. If the icon is specified as a dictionary, the image used is chosen depending on the screen's pixel density. If the number of image pixels that fit into one screen space unit equals scale, then an image with size scale * n is selected, where n is the size of the icon in the UI. At least one image must be specified. Note that 'details.path = foo' is equivalent to 'details.path = {'16': foo}'

    • tabId

      number optional

      Limits the change to when a particular tab is selected. Automatically resets when the tab is closed.

  • callback

    function optional

    The callback parameter looks like: 

    () => void

Returns

  • Promise<void>

    Chrome 116+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

setPopup()

Promise 
chrome.browserAction.setPopup(
  details: object,
  callback?: function,
)

Sets the HTML document to be opened as a popup when the user clicks the browser action icon.

Parameters

  • details

    object

    • popup

      string

      The relative path to the HTML file to show in a popup. If set to the empty string (''), no popup is shown.

    • tabId

      number optional

      Limits the change to when a particular tab is selected. Automatically resets when the tab is closed.

  • callback

    function optional

    Chrome 67+

    The callback parameter looks like: 

    () => void

Returns

  • Promise<void>

    Chrome 88+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

setTitle()

Promise 
chrome.browserAction.setTitle(
  details: object,
  callback?: function,
)

Sets the title of the browser action. This title appears in the tooltip.

Parameters

  • details

    object

    • tabId

      number optional

      Limits the change to when a particular tab is selected. Automatically resets when the tab is closed.

    • title

      string

      The string the browser action should display when moused over.

  • callback

    function optional

    Chrome 67+

    The callback parameter looks like: 

    () => void

Returns

  • Promise<void>

    Chrome 88+

    Promises are only supported for Manifest V3 and later, other platforms need to use callbacks.

Events

onClicked

chrome.browserAction.onClicked.addListener(
  callback: function,
)

Fired when a browser action icon is clicked. Does not fire if the browser action has a popup.

Parameters

  • callback

    function

    The callback parameter looks like: 

    (tab: tabs.Tab) => void