What the Fn key really does — and when to use it

The Fn key is an invisible but important element on almost every modern keyboard. It works as a modifier, combining with other keys to reveal hardware functions or alternative commands, but its behavior is significantly different in Windows and macOS.

SlashGear writes about it.

How the Fn key works in Windows and macOS

On most keyboards, you'll find the Fn key in the lower-left corner; on full-size Macs with a numeric keypad, it's in the middle, next to the Home and End keys. Newer MacBooks often use a "Globe" icon instead of the "Fn" symbol, but the purpose remains the same.

In Windows, the Fn + F1-F12 combination performs the hardware functions printed on the keys (for example, Fn + F8 will increase the volume). Pressing F1-F12 without Fn will give you standard system or application actions (for example, F5 refreshes the page).

On a Mac, it's the other way around: F1-F12 themselves control hardware capabilities (screen brightness, volume, etc.). To use the "pure" functional actions of these keys in certain applications, open "System Settings" — "Keyboard" — "Keyboard Shortcuts" — "Function Keys" and enable the option "Use F1, F2, etc. as standard function keys." After that, you will have to press Fn + F key for hardware functions (for example, Fn + F12 to increase volume).

In macOS, the Fn key can be programmed to do a separate action without a combination:

• Go to "System Preferences" — "Keyboard";
• In the "Pressing the Fn key" field, select the desired action: change the input language, show emoji and symbols, start dictation, or "Do Nothing."

In Windows, you can't assign a standalone action to the Fn key—it only works in conjunction with other keys.

So, while the Fn key acts as a modifier on both platforms, the way it's used is significantly different. Users switching from Windows to Mac or vice versa will need some time to get used to the new way of working with function keys.

As a reminder, Windows 10 will soon be celebrating its tenth anniversary—and at the same time, it's approaching the end of official support. Starting October 14, 2025, the operating system will no longer receive security updates and quality improvements.

We've also written that movies and TV have been drawing inspiration from the computer world for decades, often sacrificing truthfulness for the sake of spectacle. On-screen hackers are either romanticized or demonized, and their capabilities are often exaggerated.