Karabiner Complex Modification: Change F4 to Command + Space for Alfred

README.md

Karabiner — Change F4 to Command + Space for Alfred

This is useful for changing the default F4 key that is bound to Spotlight to launch Alfred in macOS Big Sur.

Setup:

1. Make sure you have Karabiner installed.
2. Open ~/.config/karabiner/karabiner.json.
3. Copy the rules object from below snippet and add it within profiles.complex_modifications. The basic structure of your karabiner.json file should look something like this:

{
    "global": {
      ..........
    },
    "profiles": [
        {
            "complex_modifications": {
                "parameters": {
                  ..........
                },
                "rules": [
                    {
                      "description": "F4 to CMD+SPACE",
                      "manipulators": [
                          ..........

4. Pressing F4 should now launch Alfred instead of Spotlight!

Hope this helps!

karabiner.json

{
  "rules": [
    {
      "description": "F4 to CMD+SPACE",
      "manipulators": [
        {
          "type": "basic",
          "from": {
            "key_code": "f4"
          },
          "to": [
            {
              "repeat": true,
              "key_code": "spacebar",
              "modifiers": [
                "left_gui"
              ]
            }
          ]
        }
      ]
    }
  ]
}

Thank you for sharing this!

I couldn't figure out how to add this function to Karabiner by editing karabiner.json through the steps you provided. However, I'm unsure if that was because the steps provided are a bit unclear, or if my extremely limited knowledge of code is to blame.

After some unsuccessful tries of figuring out what code to put where, I found a perhaps simpler solution:

1. Create a new JSON file in ~/.config/karabiner/assets/complex_modifications (I called it "F4_albert.json")
2. Open with a text editor and copy paste all lines of code from the code snippet provided by shripadk (labeled "karabiner.json") in to your newly created JSON file.
3. Save!
4. Open "Karabiner-Elements Settings"
5. Navigate to "Complex Modifications"
6. Click "Add rule"
7. Click "Enable" on the new rule named "F4 to CMD+SPACE"

Voilà.

The necessary lines of code are added to my karabiner.json automatically, and as a bonus, I can easily remove these lines/this function by disabling the rule in settings. I have no idea if this solution is better in any way, but I decided to leave this here in case any code illiterate people has the same struggles in the future :)

Edit: I believe that one advantage from my solution is that the changes made persists across future updates of Karabiner.

I tried to roll everything back to see if there was something wrong with your code

as I noticed my updated karabiner.json had two elements which are not in the code you provided:

• "repeat": true
• "type": "basic"

After comparing the original, unchanged karabiner.json with my failed attempt and my successful attempt, I realised that my original mistake was not adding enough of the end brackets from your code. By copy pasting line 3 to 22 "between" the square brackets after "rules" (on line 19 in an original, unedited karabiner.json), it worked perfectly.

So no! Nothing wrong with the code. Just user error.

Again, thank you, shripadk!