The F-Lock key is a toggle key on a PC compatible keyboard used to enable or disable the F1 through F12 keys' secondary functions. The F-Lock key is similar to caps lock in that it "forces" F1 through F12 to use their standard functions, as defined by the program being used.
Pressing and releasing the F-Lock key toggles on, or enables, the F1-F12 keys to use their standard functions. Pressing the F-Lock key again toggles off (disables) the F1-F12 key standard functions, and turns on the ability to use the secondary functions on those keys.
If a keyboard has a F-Lock key, it also has a F-Lock key indicator LED (light-emitting diode). When the F-Lock key is enabled, the indicator light is turned on. When the F-Lock key is disabled, the indicator light is turned off.
Today, the F-Lock key is included on very few keyboards. Instead, the Fn key is included, which allows users to activate the F1-F12 keys' secondary functions on a case-by-case basis.
What is the difference between the F-Lock and Fn keys?
Enabling F-Lock allows you to execute any standard functions tied to the F1 through F12 keys. For example, pressing F5 while using an Internet browser will refresh the page. Pressing F12 in some programs will bring up the Save As window to save a file. While F-Lock is enabled, the secondary functions on the F1-F12 keys will not be accessible.
Disabling F-Lock allows you to use the secondary functions on the F1-F12 keys and will not allow you to access the standard functions that are tied to the F1-F12 keys. For example, if F-Lock is disabled and you are using an Internet browser, pressing F5 will not refresh the page. Pressing F12 will not open the Save As window to save a file. Instead, pressing F5 might stop a CD from playing and F12 might open the calculator.
By contrast, the Fn key allows you to access the secondary functions on the F1-F12 keys at any time, without the need to disable F-Lock. For example, if you need to refresh an Internet browser page, you can press F5. If you then need to access the secondary function on the F5 key, you can press the Fn key and the F5 key.
Also, to toggle F-Lock on or off, you can press and release the F-Lock key, whereas using the Fn key requires you to press and hold the Fn key. You can then press the appropriate F1-F12 key to execute the desired function.
F1 through F12 key secondary functions
Additional features found on the function keys can include the following and more.
- Audio controls (play, stop, forward, reverse).
- Disable keyboard keys
- Open media player program
- Screen brightness settings
- Volume up and down
- Volume mute