Remap arrow key to different shortcut

Question

I am used to vim and like to move with H, J, K, L. I would like to avoid switching to the arrow keys when I am in a text field for example.

Is there a way to remap the following keys in all application on Mac OS X, so that:

← can also be triggered by OPTION H

↓ can also be triggered by OPTION J

↑ can also be triggered by OPTION K

→ can also be triggered by OPTION L

Answer 1

You can use Karabiner to remap keys.

A powerful and stable keyboard customizer for OS X.

This page details how to add custom behaviors.

Answer 2

Just done using Better Touch Tool for osx. It features a wweet options to sync your settings online. When it comes to browsing, it doesn't beat vimium. I'm using both

Answer 3

After installing Karabiner and giving required permissions, go to "Complex Modifications" tab on the left and click the "Add your own rule" button. Then paste this code:

{
"description": "Remap arrow keys to Option+JKLI",
"manipulators": [
    {
        "from": {
            "key_code": "i",
            "modifiers": {
                "mandatory": [
                    "option"
                ]
            }
        },
        "to": [
            {
                "key_code": "up_arrow"
            }
        ],
        "type": "basic"
    },
    {
        "from": {
            "key_code": "j",
            "modifiers": {
                "mandatory": [
                    "option"
                ]
            }
        },
        "to": [
            {
                "key_code": "left_arrow"
            }
        ],
        "type": "basic"
    },
    {
        "from": {
            "key_code": "k",
            "modifiers": {
                "mandatory": [
                    "option"
                ]
            }
        },
        "to": [
            {
                "key_code": "down_arrow"
            }
        ],
        "type": "basic"
    },
    {
        "from": {
            "key_code": "l",
            "modifiers": {
                "mandatory": [
                    "option"
                ]
            }
        },
        "to": [
            {
                "key_code": "right_arrow"
            }
        ],
        "type": "basic"
    }
]
}

Feel free to change to the keys you want. This remaps the arrow keys to Option+JKLI