tabs.onActivated

Fires when the active tab in a window changes. Note that the tab's URL may not be set at the time this event fired, but you can listen to tabs.onUpdated events to be notified when a URL is set.

Syntax

browser.tabs.onActivated.addListener(listener)
browser.tabs.onActivated.removeListener(listener)
browser.tabs.onActivated.hasListener(listener)

Events have three functions:

addListener(callback)
Adds a listener to this event.
removeListener(listener)
Stop listening to this event. The listener argument is the listener to remove.
hasListener(listener)
Check whether listener is registered for this event. Returns true if it is listening, false otherwise.

addListener syntax

Parameters

callback

Function that will be called when this event occurs. The function will be passed the following arguments:

activeInfo
object. ID of the tab that was made active, and ID of its window.

Additional objects

activeInfo

previousTabId
integer. The ID of the previous activated tab, if that tab is still open.
tabId
integer. The ID of the tab that has become active.
windowId
integer. The ID of the tab's window.

Examples

Listen for and log tab activation events:

function handleActivated(activeInfo) {
  console.log("Tab " + activeInfo.tabId +
              " was activated");
}

browser.tabs.onActivated.addListener(handleActivated);

Example extensions

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxOperaFirefox for Android
onActivatedChrome Full support YesEdge Full support 14Firefox Full support 45Opera Full support YesFirefox Android Full support 54

Legend

Full support  
Full support
Acknowledgements

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