tabs.connect()

Call this function to set up a connection between the extension's background scripts (or other privileged scripts, such as popup scripts or options page scripts) and any content scripts that belong to this extension and are running in the specified tab. This function returns a runtime.Port object.

When this is called, the runtime.onConnect event will be fired in any content script belonging to this extension that are running in the specified tab. The event listener will be passed another runtime.Port object. The two sides can then use the Port objects to exchange messages.

For more details, see connection-based messaging. You can message without creating a connection, for advice on choosing between the options, see Choosing between one-off messages and connection-based messaging.

Syntax

js
browser.tabs.connect(
  tabId,      // integer
  connectInfo // optional object
)

Parameters

tabId

integer. ID of the tab whose content scripts we want to connect to.

connectInfo Optional

An object with the following properties:

name Optional

string. Will be passed into runtime.onConnect event listeners in content scripts belonging to this extension and running in the specified tab.

frameId Optional

integer. Open a port to a specific frame identified by frameId instead of all frames in the tab.

Return value

runtime.Port. A port that can be used to communicate with the content scripts running in the specified tab.

Examples

In this example a background script listens for a click on a browser action, then connects to the currently active tab, then sends a message using the Port that's returned from connect():

js
function connectToTab(tabs) {
  if (tabs.length > 0) {
    let examplePort = browser.tabs.connect(tabs[0].id, {
      name: "tabs-connect-example",
    });
    examplePort.postMessage({ greeting: "Hi from background script" });
  }
}

function onError(error) {
  console.log(`Error: ${error}`);
}

browser.browserAction.onClicked.addListener(() => {
  let gettingActive = browser.tabs.query({
    currentWindow: true,
    active: true,
  });
  gettingActive.then(connectToTab, onError);
});

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Firefox for Android
Safari on iOS
connect
Chrome – Full support
Chrome 5 (Release date: 2010-05-25)
footnote Full support
Edge – Full support
Edge 79 (Release date: 2020-01-15)
footnote Full support
Firefox – Full support
Firefox 45 (Release date: 2016-03-08)
footnote Full support
Opera – Full support
Opera 15 (Release date: 2013-07-02)
footnote Full support
Safari – Full support
Safari 14 (Release date: 2020-09-16)
footnote Full support
Firefox for Android – Full support
Firefox for Android 54 (Release date: 2017-06-13)
footnote Full support
Safari on iOS – Full support
Safari on iOS 15 (Release date: 2021-09-20)
footnote Full support
connectInfo
Chrome – Full support
Chrome 41 (Release date: 2015-03-03)
footnote Full support
Edge – Full support
Edge 79 (Release date: 2020-01-15)
footnote Full support
Firefox – Full support
Firefox 45 (Release date: 2016-03-08)
footnote Full support
Opera – Full support
Opera 28 (Release date: 2015-03-10)
footnote Full support
Safari – Partial support
Safari 14 (Release date: 2020-09-16)
footnote Partial support
footnote name is supported, but frameId is not.
Firefox for Android – Full support
Firefox for Android 54 (Release date: 2017-06-13)
footnote Full support
Safari on iOS – Partial support
Safari on iOS 15 (Release date: 2021-09-20)
footnote Partial support
footnote name is supported, but frameId is not.
connectInfo.frameId
Chrome – Full support
Chrome 41 (Release date: 2015-03-03)
footnote Full support
Edge – Full support
Edge 79 (Release date: 2020-01-15)
footnote Full support
Firefox – Full support
Firefox 45 (Release date: 2016-03-08)
footnote Full support
Opera – Full support
Opera 28 (Release date: 2015-03-10)
footnote Full support
Safari – Partial support
Safari 14 (Release date: 2020-09-16)
footnote Partial support
footnote name is supported, but frameId is not.
Firefox for Android – Full support
Firefox for Android 54 (Release date: 2017-06-13)
footnote Full support
Safari on iOS – Partial support
Safari on iOS 15 (Release date: 2021-09-20)
footnote Partial support
footnote name is supported, but frameId is not.

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
Partial support
Partial support

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