F13 to F24 Key Tester

Testing F13 to F24

The keyboard above adds a row of F13 to F24 over the usual function keys, in the same groups of four. Press each extra key, or each key you’ve mapped to one, and it turns green. The picture goes by the code each press sends, which comes from the keyboard; the event log also lists the key (the name the operating system gives it) and the legacy keyCode, which is what most macro and hotkey tools ask for. Any key the picture doesn’t draw is listed under “Other keys detected”.

You can switch the row off with the F-keys control. On the plain tool page, pressing F13 or above on a full-size or TKL board adds the row by itself.

Where F13 to F24 are useful

Because ordinary keyboards lack them and applications leave them unbound, they make good private hotkeys: a macro pad key sending F15 can mute a microphone in OBS, trigger an AutoHotkey script (F15:: in the script) or switch scenes without clashing with any other shortcut. Windows handles all twelve as virtual-key codes 0x7C to 0x87. The table under this text lists each key’s codes, from the browser down to the USB report.

When a key doesn’t light up

• Nothing in the log: the key isn’t sending anything the system passes on. Check the mapping in the keyboard’s app or firmware, and that the layer it’s on is active.
• It lights another key: the mapping sends a different code. The log’s code column shows what actually arrived.
• It lights up, but the log’s key column shows another name: the operating system renamed it, as many Linux keymaps do, and applications see that name. See the questions below.
• On a Mac: F13 to F19 behave like any key, F20 is rare, and F21 to F24 usually don’t arrive.

F13 to F24: codes and names

What each extra function key sends, from the browser down to the USB report. Software that binds F13–F24 (AutoHotkey, a stream deck, a game’s key settings) may ask for any of these.