---
title: Modifiers
sidebar_label: Modifiers
hide_title: true
---

import OsLegend from "@site/src/components/codes/OsLegend";
import ToastyContainer from "@site/src/components/codes/ToastyContainer";
import Table from "@site/src/components/codes/Table";

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## Modifiers

Modifiers are the special keyboard keys: _shift_, _alt_, _control_ & _GUI_.

Modifiers can be used in two forms within ZMK:

- Modifier [Keys](#modifier-keys) → `LEFT_SHIFT`
- Modifier [Functions](#modifier-functions) → `LS(code)`

<Table group="keyboard-modifiers" />

### Modifier Keys

These act like any other key code.

- e.g. `&kp LEFT_GUI` pushes and releases the left GUI key.

### Modifier Functions

Modifier functions add one or more modifiers to a code.

These functions take the form: `XX(code)`

- Modifier functions apply a modifier to a code:
  - `&kp LS(A)` = `LEFT_SHIFT`+`A` (a capitalized **A**).
- They can be combined:
  - `&kp LC(RA(B))` = `LEFT_CONTROL`+`RIGHT_ALT`+`B`
- They can be applied to a modifier keycode to create combined modifier keys:
  - `&kp LS(LALT)` = `LEFT_SHIFT` + `LEFT_ALT`
- Some basic codes already include a modifier function in their definition:
  - `DOLLAR` = `LS(NUMBER_4)`
- There are left- and right-handed versions of each modifier (also see table above):
  - `LS(x)`, `LC(x)`, `LA(x)`, `LG(x)`, `RS(x)`, `RC(x)`, `RA(x)`, `RG(x)`
- Modified keys can safely be rolled-over. Modifier functions are released when another key is pressed.
  - Press `&kp LS(A)`, then press `&kp B`, release `&kp LS(A)` and release `&kp B` results in **Ab**. Only the A is capitalized.
