index.md

---

title: tabs.duplicate()
slug: Mozilla/Add-ons/WebExtensions/API/tabs/duplicate
page-type: webextension-api-function
tags:
  - API
  - Add-ons
  - Duplicate
  - Extensions
  - Method
  - Non-standard
  - Reference
  - WebExtensions
  - tabs
browser-compat: webextensions.api.tabs.duplicate

---

{{AddonSidebar()}}

Duplicates a tab, given its ID.

This is an asynchronous function that returns a Promise.

Syntax

let duplicating = browser.tabs.duplicate(
  tabId,              // integer
  duplicateProperties // optional object
)

Parameters

• tabId

  • : integer. The ID of the tab to be duplicated.

• duplicateProperties Optional

  • : object. An object describing how the tab is duplicated. It contains the following properties:

    • index Optional

      • : integer. The position of the new tab in the window. The value is constrained to the range zero to the number of tabs in the window.

    • active Optional

      • : boolean. Whether the tab becomes the active tab in the window. Does not affect whether the window is focused. Defaults to true.

Return value

A Promise that will be fulfilled with a {{WebExtAPIRef('tabs.Tab')}} object containing details about the duplicated tab. The Tab object only contains url, title and favIconUrl if the extension has the "tabs" permission or matching host permissions. If any error occurs the promise will be rejected with an error message.

Note: Beginning with Firefox 68, the promise returned by browser.tabs.duplicate() resolves as soon as the tab has been duplicated. Previously, the promise only resolved once the tab had fully been loaded.

Examples

Duplicate the first tab, and then log the ID of the newly created tab:

function onDuplicated(tabInfo) {
  console.log(tabInfo.id);
}

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

// Duplicate the first tab in the array
function duplicateFirstTab(tabs) {
  console.log(tabs);
  if (tabs.length > 0) {
    let duplicating = browser.tabs.duplicate(tabs[0].id);
    duplicating.then(onDuplicated, onError);
  }
}

// Query for all open tabs
let querying = browser.tabs.query({});
querying.then(duplicateFirstTab, onError);

{{WebExtExamples}}

Browser compatibility

{{Compat}}

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