Turn your Caps Lock into a system-wide vim-style navigation and editing layer — without losing its original Caps Lock function.
🇺🇸 English • 🇨🇳 中文 • 🇯🇵 日本語 • 🇩🇪 Deutsch
Caps Lock sits right on the home row, yet does almost nothing. HyperCapslock remaps it to F18 — a key that doesn't physically exist on any keyboard — then intercepts F18 + other key combos at the OS level to simulate navigation, editing, input-source switching, key combos, and shell commands.
Because F18 isn't a real modifier (not Cmd, Ctrl, Shift, or Alt), it stacks with all of them for free, without eating up any combos of its own:
So if you map Caps + H to the ← arrow key, you get these four behaviors natively:
| Combo | Action |
|---|---|
Caps + H |
← Move left |
Caps + Shift + H |
← Select left |
Caps + Alt + H |
← Move left one word |
Caps + Shift + Alt + H |
← Select left one word |
No extra configuration — system modifiers pass straight through.
And if you just tap Caps Lock and release without pressing anything else, it still toggles Caps Lock on/off as usual.
Here is the complete set of capabilities in the current version. Everything is configurable through the GUI — there are no config files to hand-edit.
A mapping is a trigger plus an action. The supported triggers are:
| Trigger | Description |
|---|---|
| Caps + key | Hold Caps (F18) and press a key, e.g. Caps + H |
| Caps + Shift + key | A separate mapping with Shift held — can bind a different action than the non-Shift version |
| Single-tap Caps (Caps×1) | Fires on a single tap of Caps (replaces the default Caps Lock toggle) |
| Double-tap Caps (Caps×2) | Fires on two quick taps of Caps; doesn't affect single-tap behavior |
| Double-tap modifier | Fires on two quick taps of a modifier, with left/right awareness: ⌘ / ⌃ / ⌥ / ⇧ / Fn |
Once you bind an action to single-tap Caps, you can still keep the original Caps Lock toggle by binding any key to the built-in Toggle Caps Lock action.
A trigger can be bound to any one of these actions:
| Action | What it does |
|---|---|
| Directional move | Up / Down / Left / Right, previous/next word, line start (Home), line end (End) |
| Jump N lines | Jump up or down any number of lines at once (e.g. 10 lines down); the count is configurable |
| Backspace / New line / Insert quotes | Backspace, open a new line below (line end + Return), insert a pair of quotes with the cursor centered |
| Switch input source | Switch directly to a specific input source (ABC, WeChat pinyin, a Japanese IME, etc.), chosen from a picker |
| Key Combo | Synthesize any system shortcut, e.g. Cmd+Shift+V, Cmd+Ctrl+Space |
| Run shell command | Run an arbitrary shell command (e.g. open -a Calculator, kick off a script) |
| Open / switch app | Launch and activate a specific application |
| Hold Modifier | Hold a modifier down for as long as the trigger is held, and release it when you let go — built for push-to-talk apps |
| Toggle Caps Lock | Explicitly toggle the system Caps Lock (to preserve the original Caps Lock function) |
| Do Nothing | Swallow the key and do nothing — handy for "disabling" a key in specific apps |
Directional move and Backspace forward whatever modifiers you're actually holding, so Caps + Shift + H selects and Caps + Option + H moves by word, all out of the box. (Switch input source, Key Combo, Run command, Open app, and Hold Modifier each carry their own explicit modifier intent and don't take part in this pass-through.)
The biggest addition over older versions: the same trigger can perform different actions in different apps.
- Add a per-app rule to any mapping: when the frontmost app matches your chosen app list, the rule's action runs; otherwise the default action runs.
- Rules are matched in order — the first match wins, and you can reorder their priority.
- Pick apps from
/Applicationswith the app picker; no need to type bundle ids by hand. - Typical uses: remap
Caps + Jto something else in one app, or use Do Nothing to fully disable a key in specific apps.
- Beyond the built-ins, you can create named custom actions (e.g. "Jump down 20 lines", "Open Calculator", "Hold right Option") and save them to the library.
- A custom action can be reused by many mappings — edit it once, and every mapping that references it updates.
- Built-in and custom actions are listed side by side, labeled "Used by N mappings", and deleting one warns you if it's still referenced.
- When an action fires, a HUD pops up at the bottom of the screen showing "trigger → action", e.g.
Caps + J → ↓. - Toggle it in Settings and tune the display duration (300–6000 ms, default 1350 ms).
- For Hold Modifier actions, the HUD stays on screen until you release the key, so you can confirm push-to-talk is active.
- The Switch input source action jumps straight to a specific input source.
- For the long-standing problem where switching to a Chinese / Japanese / Korean / Vietnamese (CJKV) IME via
TISSelectInputSourcechanges the menu-bar icon but leaves typing stuck on the previous source, three fix strategies are available on the Input Source page:- None (default — plain switch)
- Shortcut simulation (simulates the system "Select the previous input source" shortcut)
- Switching focus (forces it through by briefly switching window focus; may not work for floating / non-activatable windows)
- The fix applies only to "Caps + key → input source" mappings.
- Menu-bar control: pause / resume (Gaming Mode — temporarily disable all remapping), check for updates, more apps, open settings, quit.
- Config import / export: export the complete, self-contained
.ymlconfig in one click, or import from a file. - Auto-update: built-in Sparkle, with background and manual update checks.
- Launch at login: starts automatically at login via
SMAppService. - Hide Dock icon: run as a menu-bar-only app.
- Theme: Light / Dark / follow system.
- Localized UI: English / 中文 / 日本語 / Deutsch.
- Config compatibility: the YAML format is byte-compatible with the earlier Tauri version, so existing users'
action_mappings.yml/app_config.ymlload unchanged; unknown keys written by a newer version are preserved losslessly when an older build saves.
These are the defaults on a fresh install — all of them are customizable in the GUI:
| Combo | Action |
|---|---|
Caps + H / J / K / L |
← ↓ ↑ → Arrow keys |
Caps + A |
Home (start of line) |
Caps + E |
End (end of line) |
Caps + Y |
Previous word |
Caps + P |
Next word |
Caps + U |
Jump up 10 lines |
Caps + D |
Jump down 10 lines |
| Combo | Action |
|---|---|
Caps + I |
Backspace |
Caps + O |
New line below (line end + Return) |
Caps + N |
Insert a pair of quotes with the cursor centered |
| Combo | Action |
|---|---|
Caps + , |
Switch to ABC (English) |
Caps + . |
Switch to WeChat pinyin |
These are just defaults. You can add, remove, and rebind keys, and bind any key to any of the actions listed above.
brew install --cask XueshiQiao/tap/hypercapslockOr download the .dmg from GitHub Releases.
The app needs the Accessibility permission to install its keyboard event tap:
System Settings → Privacy & Security → Accessibility
(Input Monitoring is not needed — that's only for .listenOnly taps; this app uses an active .defaultTap, which macOS gates on Accessibility.)
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Karabiner-Elements is a powerful tool with 21k+ stars, and I used it for years. But for the specific use case of "Caps Lock as a navigation layer":
- Config complexity — Karabiner requires hand-editing JSON for non-trivial remaps. HyperCapslock has a point-and-click GUI, plus per-app rules, a custom-action library, and more.
- Footprint — Karabiner installs a kernel extension and several background processes. HyperCapslock is a single lightweight native macOS app.
- The modifier problem — Karabiner typically maps Caps Lock to a real modifier combo (e.g. Ctrl+Shift+Cmd+Opt). This "hyper key" approach works but can conflict with existing shortcuts. HyperCapslock maps to F18, which conflicts with nothing and naturally stacks with real modifiers.
If you need Karabiner's full power (mouse remapping, device-specific profiles, etc.), use Karabiner. If you mainly want vim navigation and editing everywhere with next to no setup, this might be the simpler path.
Caps Lock is remapped to F18 at the OS level via hidutil. The app then installs a CGEventTap at the HID level — a system-wide event tap that intercepts key events before any other application sees them.
When F18 is held and another key is pressed, the app swallows the original event and injects the remapped key (e.g. an arrow key) into the system input stream. Injected events carry a flag to prevent feedback loops.
State tracking uses lock-protected runtime state (OSAllocatedUnfairLock / NSLock) for thread safety between the tap thread, timer threads, and the UI. The hook callback does the bare minimum — integer comparisons and early returns — to avoid introducing input lag.
For the full technical deep-dive, see how_does_it_work.md.
- Native macOS — SwiftUI + AppKit, Swift 5 language mode, macOS 14+
- CoreGraphics
CGEventTap+hidutilfor the F18 remap; IOKit for CapsLock state; Carbon TIS for input-source switching - Sparkle for auto-update, Yams for YAML config
- A single, lightweight native process
- macOS 14+
- Xcode 16+
- XcodeGen (
brew install xcodegen)
git clone https://github.com/XueshiQiao/HyperCapslock.git
cd HyperCapslock
brew install xcodegen
xcodegen generate
open HyperCapslock.xcodeproj # Cmd+R to build & runproject.yml is the single source of truth for the Xcode project; run xcodegen generate after changing it.
xcodebuild -project HyperCapslock.xcodeproj -scheme HyperCapslock -configuration Release build- Hotkeys stop working: logs are written to
/tmp/hypercapslock-macos.log. Try removing and re-adding the app under Accessibility permissions, then relaunch. - Gaming Mode: pause/resume from the menu-bar icon to temporarily disable all remapping.
- Chinese/Japanese input switching doesn't take effect: try the Shortcut simulation or Switching focus fix strategy on the Input Source page.
GPL v3.0 — see LICENSE.