Why Mac window managers need the Accessibility permission

What the permission is for

Accessibility exists so assistive software, like screen readers and switch control, can see and operate everything on screen. Window managers use the same interface because it's the only public way to:

• find every window and its position and size,
• move and resize windows,
• notice when windows open, close, move or change focus.

There's no narrower "manage windows only" permission on macOS. That's why a simple snapping tool asks for the same permission as a screen reader.

What it could do

The interface that moves windows can also read the text of buttons, menus and many text fields in other apps, and press buttons or choose menu items. A window manager has no reason to do that, but the permission doesn't stop it. So:

• Prefer apps from developers you can identify, with a clear privacy policy.
• Prefer open-source apps if you can read or trust the code, or closed-source apps that state plainly what they collect.
• Remove the permission from apps you no longer use.

How to grant it

1. Open System Settings → Privacy & Security → Accessibility.
2. Turn on the switch next to the app. If it isn't listed, click + and choose it from Applications.
3. You may need to quit and reopen the app.

Most apps open this pane for you on first launch.

How to revoke it

Turn off the app's switch in the same list, or select it and click − to remove it entirely. The app loses access immediately.

Why it stops working

• The app moved or was updated. macOS ties the permission to the app's identity and location. Run apps from the Applications folder, not from a disk image or Downloads. After an update, if the app says it has no access while the switch is on, remove it with − and add it again.
• Two window tools at once. They don't break the permission, but they fight over the same windows, which looks like a malfunction. Run one.
• Managed Macs. On a work Mac, your organisation's device management may block or pre-approve Accessibility for certain apps.

Other permissions you may be asked for

A window manager that only moves windows needs Accessibility and nothing else.

Accessibility vs turning off SIP

System Integrity Protection (SIP) protects macOS system files and processes. A few power tools ask you to partly disable it, from Recovery mode, so they can inject code into the Dock to do things the Accessibility interface can't, such as creating Spaces or moving windows between them instantly. yabai is the best-known example; its basic tiling works with SIP on. See yabai without SIP.

Turning off SIP is a much bigger decision than granting Accessibility: it lowers protection for the whole system. Most window managers don't need it.

What Ribbon asks for

Ribbon needs the Accessibility permission only. No SIP changes, no kernel extensions, no account and no telemetry; the app contacts the network only to validate its licence and check for updates. The details are in the privacy policy and the setup guide. You can see what the app does before installing anything in the live demo, and pricing is $9.99 once.