# Quantum Keycodes Quantum keycodes allow for easier customization of your keymap than the basic ones provide, without having to define custom actions. All keycodes within quantum are numbers between `0x0000` and `0xFFFF`. Within your `keymap.c` it may look like you have functions and other special cases, but ultimately the C preprocessor will translate those into a single 4 byte integer. QMK has reserved `0x0000` through `0x00FF` for standard keycodes. These are keycodes such as `KC_A`, `KC_1`, and `KC_LCTL`, which are basic keys defined in the USB HID specification. On this page we have documented keycodes between `0x00FF` and `0xFFFF` which are used to implement advanced quantum features. If you define your own custom keycodes they will be put into this range as well. ## QMK Keycodes :id=qmk-keycodes |Key |Aliases |Description | |-----------------|---------|-------------------------------------------------------------------------------------------------------------------------------------------------| |`QK_BOOTLOADER` |`QK_BOOT`|Put the keyboard into bootloader mode for flashing | |`QK_DEBUG_TOGGLE`|`DB_TOGG`|Toggle debug mode | |`QK_CLEAR_EEPROM`|`EE_CLR` |Reinitializes the keyboard's EEPROM (persistent memory) | |`QK_MAKE` | |Sends `qmk compile -kb (keyboard) -km (keymap)`, or `qmk flash` if shift is held. Puts keyboard into bootloader mode if shift & control are held | |`QK_REBOOT` |`QK_RBT` |Resets the keyboard. Does not load the bootloader | !> Note: `QK_MAKE` requires `#define ENABLE_COMPILE_KEYCODE` in your config.h to function.