A keyboard layer changes what a group of keys does while a layer key is held. The idea is similar to holding Shift for capital letters, except the output can be navigation, symbols, or application shortcuts.
This small layer puts arrow keys under the right hand. Hold Caps, then use H, J, K, and L. You can also use the physical Caps Lock key while this page has focus.
Interactive lab
Caps layer
Hold physical Caps Lock, or toggle the on-screen Caps key, then press H, J, K, or L.
Activate this control to toggle H, J, K, and L between letters and arrow keys. The physical Caps Lock key works as a hold control while this page has focus.
Why a hold matters#
The layer stays active only while Caps is held. Releasing it returns the letters immediately. That makes accidental mode changes less likely because there is no hidden state to remember.
What the demo leaves out#
A system-level remap also needs tap-versus-hold timing, application exceptions, and a way to preserve Caps Lock when it is genuinely needed. Those details belong in the operating-system configuration. This lab isolates the part worth feeling first: whether arrows under the home row make sense to your hands.