Do you know how you can double press the side button of your Apple Watch and then move it over a contactless terminal to pay with your credit card? Wouldn't it be great if you could do the same with your Mac login password? Instead of having to type your password to authenticate, you could double-tap the side button on the Apple Watch to do so instantly.
Well, now you can do exactly this, if you are running macOS Catalina.
How to use your Apple Watch to enter Mac passwords
This tip comes to us through Mac writer Kirk McElhearn. And the good news is that if you already use your Apple Watch to unlock your Mac automatically, then you don't need to do anything. Every time the Mac needs your administrator password (the one you use to log in to your Mac and to authenticate when you change certain settings), you will get a small touch on your wrist and this dialog box will appear on your Mac's screen:
Then you have two options. You can press the side button of your Apple Watch twice to authenticate, or click Use password … to do just that.
What about Touch ID?
The "bad" news is that if you have a Mac with Touch ID, you get three options instead of two. Even if you use your Apple Watch, you will be asked to place your finger on the Touch ID sensor through the dialog box below:
At the same time, you will feel (and hear) the tactical warning of the Apple Watch. You can choose to press the side button of the watch twice, touch the Touch ID sensor or go to the old school and write your Mac login.
In practice, it really doesn't matter. After all, is it more or less convenient to squeeze the Apple Watch twice than to put a finger on a sensor? The Apple Watch allows automatic screen unlocking, just like Face ID on the iPad. It just happens, without your interaction. But to confirm your intention to authenticate, the watch requires you to explicitly allow the action.
Between this and the new Sidecar feature in macOS Catalina that allows you to use your iPad as an external display for your Mac, Apple is really facilitating the joint use of all your Apple devices.