Do you know what the Option key on your Mac keyboard does? It’s actually one of the best little-known features in macOS, and hides countless extra settings and shortcuts. Let’s take a closer look.

What Does the Option Key Do on a Mac Keyboard?

The Option key on a Mac keyboard, often labeled “Alt” on older models, is a modifier key. It changes the available options in various menus and provides shortcuts when combined with other keys.

Apple does a poor job of explaining exactly what it does, so many people stumble upon it by accident. To see how it works, open a menu at the top of your screen and press the Option key. Some of the menu options will change right before your eyes.

This happens throughout macOS, and in many apps as well. The easiest way to find things is simply to experiment. Whenever you’ve got menus open, including right-click context menus, press the Option key and see if anything happens.

To get you started, here are some tricks that I use daily.

Get Fine Control of Volume and Brightness

The volume controls in macOS are split into 16 steps. Sometimes, the jump from one step to another is a little more than you’d like. But if you hold down Shift+Option and then hit the volume buttons, the number of steps increases to 64. It gives you much more precise control over your Mac’s speakers.

You can do the same thing with the brightness controls, where it’s perhaps a little less useful, but certainly worth knowing about.

Restart and Shut Down Quickly

If you see menu items ending with an ellipsis—three dots—it means there will be another step after you click. This will often ask for confirmation that you want to continue with your selected action.

So, under the Apple menu in the top left corner of the screen, the Restart, Shut Down, and Log Out options all have these dots. Click them, and you’ll see a dialog box prompting you to confirm.

But pressing the Option key makes the dots disappear. You can now bypass the warning and shut down, restart, or log out with just a single click.

Force Quit Apps

When an app crashes, you can normally right-click on its icon in the Dock and select “Force Quit” to shut it down.

But sometimes an app hangs, becomes completely unresponsive, and the Force Quit option doesn’t appear. Sometimes you just want to force quit an app to end a process that hasn’t crashed. To make it happen, right-click the icon in the Dock and hold down the Option key. “Quit” will change to “Force Quit” and you can now shut it down.

Access the “Save As” Option

A common option that’s missing in a lot of Mac apps is “Save As” in the File menu. You normally get a “Duplicate” option instead, which creates a copy of the file you’re working on that you can save separately. It’s a similar principle, but involves a few extra steps.

If you’re used to the Windows way of doing things, select “File,” hold down the Option key, and “Duplicate” will change to “Save As.” You can now quickly save your file with a different name or in a different file type.

Get Info on Multiple Items

To check out the size of a file or folder, or see other properties relating to it, right-click it and hit “Get Info.” Select multiple files and do this, and you’ll get separate info boxes for each one.

To see the size of multiple files or folders combined, select them, right-click, and hold down the Option key. “Get Info” now changes to “Show Inspector,” and clicking that opens a single “Multiple Item Info” box.

Close Multiple Windows at Once

When you’ve got several windows open within the same app, and you want to shut them all but keep the app itself running, you have to click the red button in the top corner of each window. Alternatively, you can cut to the chase by going to “File” and pressing the Option key, and you’ll see that “Close Window” changes to “Close All.”

Cut (Move) and Paste Files

It isn’t obvious how to cut-and-paste files or folders in macOS. You might expect Edit > Cut to do it, but it’s grayed out.

What you can do instead is select the file and copy it to your clipboard by using Edit > Copy or the Command+C keyboard shortcut. Navigate to the location where you want to paste it. Now select “Edit” and press the Option key, whereupon “Paste” will change to “Move Item Here.”

Click this to move the files, which has the same effect as a cut-and-paste. Want to easily move files and folders in Finder? Add Windows-style cut and paste with free app Command X.

Quickly Duplicate Files

To quickly duplicate a file or folder, select it (you can choose more than one), hold down the Option key, and then drag and drop it either to the same location or a different folder. You’ll see a green “+” icon appear to show that you’re creating a copy.

Change the Default App for File Types

To open a file in an app that’s not your default app for that file type, right-click on it and select “Open With,” then choose the app from the list. To change this permanently, right-click on the file, hold down the Option key and “Open With” will change to “Always Open With.”

Change the Window Tiling Options

In macOS Sequoia, hover your mouse pointer over the green icon in the top left corner of a window to see options for tiling and arranging your windows on the screen. Hold down the Option key, and you will see a different set of tiling options.

The Option key also changes the green button from the default full-screen mode to a “maximize” option, where the app scales to the height of the screen instead.

Make Text Bigger on Websites (Without Zooming)

In the Safari View menu, there are Zoom In and Zoom Out options that make everything on the page either bigger or smaller. Hold down the Option key and these settings change to Make Text Bigger and Make Text Smaller. These change the font size while leaving images and other interface elements pretty much the same. It’s a simple way to make pages more readable if you prefer larger text.

Even More Keyboard Shortcuts

There are even more keyboard shortcuts attached to the Option key that you might not be aware of. It’s worth experimenting to see what you can find.

Some useful examples include Option+F3, a shortcut to System Settings, and Option+Command+Backspace, which instantly deletes a file, bypassing the Trash.

In a text app, Option+Backspace deletes one word at a time rather than one character at a time. You can also use the Option key to type special characters.

The Keyboard Viewer tool lets you see which characters are mapped to certain keys. To enable it, go to System Settings > Keyboard, select “Edit” under Text Input, then toggle on “Show Input menu in the menu bar.” Now click the Input Menu icon and select “Keyboard Viewer.” Press the Option key to see all the special characters you can type.

Use the Option Key In Apps as Well

The option key is so useful that it’s surprising Apple hides its utility so well in macOS. I’ve covered a selection of the shortcuts that I find most useful, but there are no doubt many more that you can find.

It’s worth testing the Option key in your apps as well. Some may have app-specific shortcuts on top of the universal macOS ones. Every time you see a menu, just give the button a quick press and see what happens.