Opening a WordPress menu link in a new window or tab it is actually easy. But sometimes, it can be tricky.
So you have built a WordPress menu and you want one of the menu items to open in a new tab. Or a new window on your Firefox, Chrome or whatever browser you use. That is probably you have a menu item that links to another website, or to a .pdf or maybe a page with testimonials or whatever.
First you have to login to your WordPress dashboard and then go to Menus page by clicking on Menus link under Appearance. You will land on page which will look like this screenshot:
After you select the menu you want to edit you will notice the menu items. Click the arrow on the right of the item you want open in a new tab to reveal additional configuration options. If you cannot see any option says "Open link in a new tab" then you have to click on top right Screen Options, under the Howdy, user name and next to Help button.
Once you click on Screen Options tab it will expand and you will see some options listed. Under Show advanced menu properties, check the first one called Link Target. Once you check that, you will notice under each menu item this new option: Open link in a new tab. For the menu item which you want to open in a new tab, just check that option:
What will this actually do? It will add the target="_blank" to the HTML code of that
<a> element. That is all. Good Luck!