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.

A Promise that will be fulfilled with a 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.

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);

• tabs-tabs-tabs