Should you have multiple tabs open in Safari on your iPhone or iPad and need to close them quickly, it can be time consuming to individually close each out by taping on “X” for each one. Here is a quick method that will let you close all tabs at once. 

Open Safari on your iPhone/ipad > locate the tab switch icon, being the 2 overlapping squares. On iPad this is located in the upper right hand corner, whilst on iphone, its in the lower right hand corner. 

If you hold the button for a few seconds longer, also known as a long press, you will see a menu show, which has the option “Close All Tabs”, with a number confirming the current amount of open tabs. 

Safari will then ask you to confirm in another pop up menu, simply tab on “Close All Tabs”, which will close all open browser tabs. 

When Safari asks you to confirm with another pop-up, tap “Close All Tabs” again. After that, all of your browser tabs will close.

Source & Further Reading:  https://www.howtogeek.com/704977/how-to-close-all-safari-tabs-at-once-on-iphone-and-ipad/