Macros
Macros allow you to send multiple keystrokes when pressing just one key. QMK has a number of ways to define and use macros. These can do anything you want: type common phrases for you, copypasta, repetitive game movements, or even help you code.
!> Security Note: While it is possible to use macros to send passwords, credit card numbers, and other sensitive information it is a supremely bad idea to do so. Anyone who gets a hold of your keyboard will be able to access that information by opening a text editor.

SEND_STRING() & process_record_user

Sometimes you want a key to type out words or phrases. For the most common situations, we've provided SEND_STRING(), which will type out a string (i.e. a sequence of characters) for you. All ASCII characters that are easily translatable to a keycode are supported (e.g. qmk 123\n\t).
Here is an example keymap.c for a two-key keyboard:
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enum custom_keycodes {
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QMKBEST = SAFE_RANGE,
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};
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bool process_record_user(uint16_t keycode, keyrecord_t *record) {
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switch (keycode) {
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case QMKBEST:
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if (record->event.pressed) {
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// when keycode QMKBEST is pressed
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SEND_STRING("QMK is the best thing ever!");
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} else {
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// when keycode QMKBEST is released
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}
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break;
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}
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return true;
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};
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const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
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[0] = {
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{QMKBEST, KC_ESC},
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// ...
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},
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};
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What happens here is this: We first define a new custom keycode in the range not occupied by any other keycodes. Then we use the process_record_user function, which is called whenever a key is pressed or released, to check if our custom keycode has been activated. If yes, we send the string "QMK is the best thing ever!" to the computer via the SEND_STRING macro (this is a C preprocessor macro, not to be confused with QMK macros). We return true to indicate to the caller that the key press we just processed should continue to be processed as normal (as we didn't replace or alter the functionality). Finally, we define the keymap so that the first button activates our macro and the second button is just an escape button.
You might want to add more than one macro. You can do that by adding another keycode and adding another case to the switch statement, like so:
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enum custom_keycodes {
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QMKBEST = SAFE_RANGE,
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QMKURL,
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MY_OTHER_MACRO,
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};
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bool process_record_user(uint16_t keycode, keyrecord_t *record) {
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switch (keycode) {
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case QMKBEST:
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if (record->event.pressed) {
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// when keycode QMKBEST is pressed
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SEND_STRING("QMK is the best thing ever!");
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} else {
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// when keycode QMKBEST is released
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}
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break;
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case QMKURL:
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if (record->event.pressed) {
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// when keycode QMKURL is pressed
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SEND_STRING("https://qmk.fm/\n");
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} else {
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// when keycode QMKURL is released
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}
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break;
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case MY_OTHER_MACRO:
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if (record->event.pressed) {
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SEND_STRING(SS_LCTL("ac")); // selects all and copies
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}
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break;
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}
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return true;
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};
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const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
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[0] = {
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{MY_CUSTOM_MACRO, MY_OTHER_MACRO},
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// ...
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},
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};
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Advanced Macros

In addition to the process_record_user() function, is the post_process_record_user() function. This runs after process_record and can be used to do things after a keystroke has been sent. This is useful if you want to have a key pressed before and released after a normal key, for instance.
In this example, we modify most normal keypresses so that F22 is pressed before the keystroke is normally sent, and release it only after it's been released.
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static uint8_t f22_tracker;
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bool process_record_user(uint16_t keycode, keyrecord_t *record) {
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switch (keycode) {
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case KC_A ... KC_F21: //notice how it skips over F22
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case KC_F23 ... KC_EXSEL: //exsel is the last one before the modifier keys
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if (record->event.pressed) {
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register_code(KC_F22); //this means to send F22 down
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f22_tracker++;
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register_code(keycode);
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return false;
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}
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break;
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}
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return true;
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}
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void post_process_record_user(uint16_t keycode, keyrecord_t *record) {
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switch (keycode) {
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case KC_A ... KC_F21: //notice how it skips over F22
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case KC_F23 ... KC_EXSEL: //exsel is the last one before the modifier keys
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if (!record->event.pressed) {
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f22_tracker--;
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if (!f22_tracker) {
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unregister_code(KC_F22); //this means to send F22 up
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}
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}
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break;
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}
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}
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TAP, DOWN and UP

You may want to use keys in your macros that you can't write down, such as Ctrl or Home. You can send arbitrary keycodes by wrapping them in:
    SS_TAP() presses and releases a key.
    SS_DOWN() presses (but does not release) a key.
    SS_UP() releases a key.
For example:
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SEND_STRING(SS_TAP(X_HOME));
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Would tap KC_HOME - note how the prefix is now X_, and not KC_. You can also combine this with other strings, like this:
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SEND_STRING("VE"SS_TAP(X_HOME)"LO");
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Which would send "VE" followed by a KC_HOME tap, and "LO" (spelling "LOVE" if on a newline).
Delays can be also added to the string:
    SS_DELAY(msecs) will delay for the specified number of milliseconds.
For example:
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SEND_STRING("VE" SS_DELAY(1000) SS_TAP(X_HOME) "LO");
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Which would send "VE" followed by a 1-second delay, then a KC_HOME tap, and "LO" (spelling "LOVE" if on a newline, but delayed in the middle).
There's also a couple of mod shortcuts you can use:
    SS_LCTL(string)
    SS_LSFT(string)
    SS_LALT(string) or SS_LOPT(string)
    SS_LGUI(string), SS_LCMD(string) or SS_LWIN(string)
    SS_RCTL(string)
    SS_RSFT(string)
    SS_RALT(string), SS_ROPT(string) or SS_ALGR(string)
    SS_RGUI(string), SS_RCMD(string) or SS_RWIN(string)
These press the respective modifier, send the supplied string and then release the modifier. They can be used like this:
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SEND_STRING(SS_LCTL("a"));
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Which would send Left Control+a (Left Control down, a, Left Control up) - notice that they take strings (eg "k"), and not the X_K keycodes.

Alternative Keymaps

By default, it assumes a US keymap with a QWERTY layout; if you want to change that (e.g. if your OS uses software Colemak), include this somewhere in your keymap:
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#include "sendstring_colemak.h"
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Strings in Memory

If for some reason you're manipulating strings and need to print out something you just generated (instead of being a literal, constant string), you can use send_string(), like this:
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char my_str[4] = "ok.";
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send_string(my_str);
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The shortcuts defined above won't work with send_string(), but you can separate things out to different lines if needed:
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char my_str[4] = "ok.";
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SEND_STRING("I said: ");
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send_string(my_str);
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SEND_STRING(".."SS_TAP(X_END));
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Advanced Macro Functions

There are some functions you may find useful in macro-writing. Keep in mind that while you can write some fairly advanced code within a macro, if your functionality gets too complex you may want to define a custom keycode instead. Macros are meant to be simple.
?> You can also use the functions described in Useful function and Checking modifier state for additional functionality. For example, reset_keyboard() allows you to reset the keyboard as part of a macro and get_mods() & MOD_MASK_SHIFT lets you check for the existence of active shift modifiers.

record->event.pressed

This is a boolean value that can be tested to see if the switch is being pressed or released. An example of this is
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if (record->event.pressed) {
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// on keydown
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} else {
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// on keyup
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}
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register_code(<kc>);

This sends the <kc> keydown event to the computer. Some examples would be KC_ESC, KC_C, KC_4, and even modifiers such as KC_LSFT and KC_LGUI.

unregister_code(<kc>);

Parallel to register_code function, this sends the <kc> keyup event to the computer. If you don't use this, the key will be held down until it's sent.

tap_code(<kc>);

Sends register_code(<kc>) and then unregister_code(<kc>). This is useful if you want to send both the press and release events ("tap" the key, rather than hold it).
If TAP_CODE_DELAY is defined (default 0), this function waits that many milliseconds before calling unregister_code(<kc>). This can be useful when you are having issues with taps (un)registering.
If the keycode is KC_CAPS, it waits TAP_HOLD_CAPS_DELAY milliseconds instead (default 80), as macOS prevents accidental Caps Lock activation by waiting for the key to be held for a certain amount of time.

tap_code_delay(<kc>, <delay>);

Like tap_code(<kc>), but with a delay parameter for specifying arbitrary intervals before sending the unregister event.

register_code16(<kc>);, unregister_code16(<kc>); and tap_code16(<kc>);

These functions work similar to their regular counterparts, but allow you to use modded keycodes (with Shift, Alt, Control, and/or GUI applied to them).
Eg, you could use register_code16(S(KC_5)); instead of registering the mod, then registering the keycode.

clear_keyboard();

This will clear all mods and keys currently pressed.

clear_mods();

This will clear all mods currently pressed.

clear_keyboard_but_mods();

This will clear all keys besides the mods currently pressed.

Advanced Example:

Super ALT↯TAB

This macro will register KC_LALT and tap KC_TAB, then wait for 1000ms. If the key is tapped again, it will send another KC_TAB; if there is no tap, KC_LALT will be unregistered, thus allowing you to cycle through windows.
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bool is_alt_tab_active = false; // ADD this near the begining of keymap.c
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uint16_t alt_tab_timer = 0; // we will be using them soon.
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enum custom_keycodes { // Make sure have the awesome keycode ready
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ALT_TAB = SAFE_RANGE,
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};
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bool process_record_user(uint16_t keycode, keyrecord_t *record) {
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switch (keycode) { // This will do most of the grunt work with the keycodes.
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case ALT_TAB:
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if (record->event.pressed) {
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if (!is_alt_tab_active) {
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is_alt_tab_active = true;
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register_code(KC_LALT);
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}
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alt_tab_timer = timer_read();
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register_code(KC_TAB);
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} else {
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unregister_code(KC_TAB);
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}
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break;
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}
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return true;
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}
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void matrix_scan_user(void) { // The very important timer.
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if (is_alt_tab_active) {
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if (timer_elapsed(alt_tab_timer) > 1000) {
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unregister_code(KC_LALT);
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is_alt_tab_active = false;
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}
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}
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}
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Last modified 7mo ago