tabs.getZoomSettings()

tabId Optional

integer. The ID of the tab to get the current zoom settings from. Defaults to the active tab of the current window.

A Promise that will be fulfilled with a tabs.ZoomSettings object representing the tab's current zoom settings. If the tab could not be found or some other error occurs, the promise will be rejected with an error message.

Get the zoom settings for the current tab:

function onGot(settings) {
  console.log(settings);
}

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

let gettingZoomSettings = browser.tabs.getZoomSettings();
gettingZoomSettings.then(onGot, onError);