How to Close All Tabs in the Safari Browser
Use the Tab menu to close all open tabs simultaneously. Tap and hold the Tab button, which looks like two stacked squares. When you tap it, the button opens a new window, but when you keep your finger pressed on it, the Tabs menu appears. The Tabs menu includes an option to close all open tabs, except for the page you’re currently viewing.
How to Close All Tabs Without Opening the Safari Browser
When you cannot open Safari to close all the open tabs on your iPhone or iPad, clear the Safari cache of website data. This approach is the sledgehammer way to close tabs and should only be done when you cannot close tabs through the web browser. Clearing this data erases all the cookies stored on your device, which means you will need to log back in to websites that ordinarily keep you logged in between visits. From in the iPhone or iPad Settings app, browse to the Safari section and select Clear History and Website Data. Confirm your selection in the pop-up screen.