The Alt key on a Mac is called Option (⌥)

Why it happens

Apple has always called this key Option, though some keyboards print alt on it as well. On the left it sits between Control and Command, and there's a second one to the right of the space bar. Like Alt, it gives other keys and menus a second set of choices.

How to fix it

1. Find the key. On a Mac keyboard, look left of the space bar: Command (⌘) is right next to it, then Option (⌥), then Control. There's a second Option key on the right, after the right-hand Command.

2. Type a symbol: hold Option and press a letter or number. On a US layout, Option-G types ©, Option-2 types ™ and Option-8 types •. Other layouts put some symbols on different keys.

3. See hidden menu items: open a menu, then hold Option. Some items change while you hold it, for example Close becomes Close All in many apps' File menu.

4. Get extra details: hold Option while you click some menu bar icons, such as Wi-Fi or Sound, to see more information and settings.

5. To see every symbol your layout can make, turn on Show Input menu in menu bar, then choose Show Keyboard Viewer from that menu and hold Option. The keys show what each one types.

   Keyboard›Text Input›Edit…›Show Input menu in menu bar

Still not fixed?

1. On a keyboard made for other computers, the Alt key works as Option, and the key beside it works as Command, so the two can feel swapped. Open Keyboard Shortcuts… > Modifier Keys, pick that keyboard, and set the keys the way you like.

   Keyboard›Keyboard Shortcuts…›Modifier Keys

2. If you're used to AltGr for accents and symbols, use Option instead. You can also press and hold a letter, like e, to pick an accented version from a small pop-up.

3. If Option does nothing at all, check the same Modifier Keys page in case Option was set to No Action or swapped with another key, and click Restore Defaults if so.

4. If one Option key works and the other doesn't, the key itself may be faulty. Clean around it, and if it still won't respond, contact Apple Support or a repair shop for a keyboard check.