There are several times when you may close a tab by mistake in the browser, if you are Google Chrome user, you can easily open the last closed tab, by opening a blank tab and selecting the link from the recently closed section.
When you close a tab accidentally in opera, you can quickly reopen the closed tab by using the shortcut key Ctrl + Z, which is a undo function.
Clicking this shortcut key will reopen the last closed tab in Opera. This is one shortcut we definitely recommend Opera users to remember.
If you are having trouble with Opera closing itself without a warning, head to our tutorial: How to Setup Opera to Prompt on Exit?