To see this trick in action, launch the Notes app, open a new note, and start typing. Next, hold your iPhone in your hand and physically shake the device lightly. When you do this, you will see an “Undo Typing” popup on your screen. Tap Undo to remove all previously entered text. Of course, if you accidentally shake your iPhone, you can press Undo and start typing again without deleting anything.
It’s important to note that the shake-to-undo functionality is not limited to erasing typos. Depending on when you shake, iPhone modifies the last typing-related action you performed. For example, if your last action was to delete a series of words, shake the device and press “undo” to undo the deleted words. It also works for bodies of text copied and pasted into the text area of the Apple app you’re typing. Essentially, this is a generic undo tool that skips back one app action. If you need to undo a series of actions that contain typos, you can do it as many times as you like.