Remapping that follows you off macOS.

Karabiner-Elements is excellent on macOS: Simple and Complex Modifications, per-device rules, profiles, a web-UI generator, free and open source. If you live on macOS and remap your keyboard, it's hard to beat.

Rebind is for the moment you need more reach. The same remaps run on Windows and Linux, mouse transforms sit alongside keyboard, and with Rebind Link, output leaves through a dedicated USB device as standard HID. Underneath is a full scripting runtime: an SDK covering HTTP, WebSockets, screen sampling, window control, macros, and shared-memory IPC.

This core remap runs on Windows, macOS, and Linux:

-- rebind: name=Caps to Ctrl
-- rebind: version=1.0.0
-- rebind: min_sdk=3.0.0

function OnDown(key)
  if key == "CapsLock" then
    HID.Down("LCtrl")
    return false  -- block CapsLock
  end
  return true
end

function OnUp(key, duration)
  if key == "CapsLock" then
    HID.Up("LCtrl")
    return false
  end
  return true
end

Use Karabiner-Elements when you live on macOS, focus on keyboard remapping, and want a mature open-source tool with a web-UI generator.

Use Rebind when you also work on Windows or Linux and want one config everywhere, want mouse transforms alongside keyboard, or want automation beyond remapping: HTTP, screen, window, macros.

Use both: keep Karabiner on macOS and add Rebind for cross-OS and hardware-backed work.

Does Rebind run on Windows and Linux? Yes. Core remapping and HID output run on Windows 10/11, macOS, and Linux x86_64. Several OS integrations differ; check the platform matrix.

Can I import my Karabiner JSON? No direct import. The concepts map cleanly, and RebindGPT can draft a remap from a plain-English description.

Does Rebind remap the mouse too? Yes. Keyboard and mouse are first-class, including button transforms. Transforming relative movement needs Rebind Link.