Download Capslox and install it.

On first launch, Capslox creates a default config file with navigation, selection, and text editing shortcuts:

• macOS: ~/.config/capslox/keymap.jsonc
• Windows: %APPDATA%\Capslox\keymap.jsonc

The config uses JSONC format (JSON with comments). Edit the file with any text editor. Changes are detected and applied instantly — no restart needed.

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Capslox turns Caps Lock into a powerful modifier key — move the cursor, select, and delete text without your fingers leaving the home row.

Try the Interactive Tutorial — a game-like walkthrough that guides you through each shortcut step by step.

The rest of this guide covers how to customize your own bindings beyond the defaults.

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Capslox configuration has four core concepts: Layers, Bindings, Actions, and Custom Modifiers.

A layer is a named group of bindings. The base layer is always active. Other layers activate on top of it, forming a stack.

Layer types:

• Base — Always active. Identified by "id": "base".
• Manual — Activated by layer_push, layer_toggle, or layer_swap actions in bindings.
• AutoApp — Activates automatically when a matching app gains focus.

When a key is pressed, the engine checks layers top-down. The first layer with a matching binding wins.

A binding maps a trigger key (with optional modifiers) to an action.

Simple binding — Caps Lock + J sends Left arrow:

"caps-j": "left"

Binding types:

• Direct — Triggers on key-down. The most common type.
• ModTap — Hold for modifier, tap for action. "caps": { "type": "mod_tap", "tap": "esc" }
• LongPress — Short press for one action, long press for another.

Capslox supports mod_tap (hold for modifier, tap for action) and long_press (action depends on press duration) as its two key modes. See Configuration Reference: Key Modes.

Key names use physical US QWERTY positions, lowercase. Modifiers: ctrl, shift, opt/alt, cmd/win, plus super as a cross-platform alias for cmd/win. Prefer the platform-native name — see Configuration Reference: Modifiers. Hyphen joins combos: cmd-shift-a.

See Configuration Reference: Key Vocabulary for the complete key list.

An action is what happens when a binding triggers.

The simplest action is a key press — just write the key name as a string:

"cx-h": "left"                    // send Left arrow
"cx-u": "cmd-left backspace"      // select to line start, then delete
"cx-cmd-e": "up*5"                // press Up 5 times

Beyond key presses, actions can control layers, manage clipboard slots, switch windows, and more. Each uses the "action" field:

{ "action": "layer_toggle", "target": "vim" }
{ "action": "clipboard_paste", "slot": "1" }
{ "action": "show_cheat_sheet" }

See Configuration Reference: Actions for all action types.

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Beyond the built-in modifiers (ctrl, shift, alt, super), Capslox lets you turn any physical key into a custom modifier — give it an alias, then use that alias in your bindings.

For example, you can register Caps Lock as the cx modifier with a tap action of Esc:

"custom_modifiers": { "caps": { "alias": "cx", "tap": "esc" } }

• Names Caps Lock as cx
• Hold Caps Lock → activates the cx modifier
• Tap Caps Lock → sends Esc

The "esc" tap in the example above is for illustration. The keymap Capslox ships with uses toggle_caps_lock as the tap action — tap can be any action.

Now you can use cx as a prefix in your bindings:

"cx-e": "up",
"cx-d": "down",
"cx-s": "left",
"cx-f": "right"

Many-to-one

Multiple physical keys can share the same alias. For example, if your keyboard lacks a dedicated Caps Lock key (like the HHKB), you can register Tab as cx too:

{
  "custom_modifiers": {
    "caps": { "alias": "cx", "tap": "esc" },
    "tab": "cx"
  },
  "layers": [
    {
      "id": "base",
      "on_miss": "pass_to_os",
      "bindings": {
        "cx-e": "up",
        "cx-d": "down"
      }
    }
  ]
}

Now both Caps Lock and Tab act as cx modifiers.

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Press caps-shift-/ to open Capslox's built-in keymap editor, or open keymap.jsonc in your editor. Use the full example below as a reference, then add the new cx-tab binding and the browse layer to your existing config:

{
  "version": "1.0",
  "custom_modifiers": { "caps": { "alias": "cx", "tap": "esc" } },
  "layers": [
    {
      "id": "base",
      "on_miss": "pass_to_os",
      "bindings": {
        "cx-e": "up",
        "cx-d": "down",
        "cx-s": "left",
        "cx-f": "right",
        // Your new binding:
        "cx-tab": { "action": "layer_toggle", "target": "browse" },
        "cx-m": "enter"
      }
    },
    {
      "id": "browse",
      "activation": { "type": "manual" },
      "on_miss": "continue",
      "bindings": {
        "e": "pageup",
        "d": "pagedown",
        "s": "ctrl-shift-tab",
        "f": "ctrl-tab"
      }
    }
  ]
}

Save the file. Capslox detects the change and reloads the config. In your browser, press caps-tab to switch to the browse layer, then press e / d / s / f to navigate pages.

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Capslox supports many more features:

• App-specific bindings (different behavior per app) — see Configuration Reference: When Clause
• Multiple layers — see Configuration Reference: Layers
• Clipboard slots — see Configuration Reference: Clipboard actions
• Window management — see Configuration Reference: Window actions