Disable Cmd-Tab, Spotlight & screenshots on a Mac

To hand a Mac to the public you have to close the ways out, Cmd-Tab, Cmd-Q, Spotlight, the screenshot tools and Mission Control. The awkward part: they don’t all work the same way, so there’s no single macOS setting that blocks the lot, and full-screen Safari stops none of them.

Why it’s not one switch

Cmd-Tab & Cmd-Q

App-switching and quit. These reach an event tap, so they can be caught and swallowed before macOS acts on them.

Spotlight (Cmd-Space)

Dispatched from a privileged WindowServer path, so it never reaches an app’s event tap. The dependable fix is toggling the underlying system “symbolic hotkey” off.

Screenshots (⌘⇧3/4/5)

Same privileged path as Spotlight, an ordinary key blocker won’t stop them; the symbolic-hotkey toggle does.

Mission Control & media keys

Exposé, Dashboard and the media/aux keys are separate again, and each needs handling to fully seal the screen.

The one-step way: Canned Web

Canned Web blocks the whole set at once. Enter a URL, hold ⌘⇧S, and while the site is sealed it swallows the shortcut keys and toggles off the privileged ones (Spotlight, screenshots) that a key blocker can’t touch. It’s scoped to the sealed session and restored at logout, so nothing is changed permanently. No MDM, one-time €49 per machine, 14-day trial.

FAQ

Can you disable Cmd-Tab on a Mac?

Yes. Cmd-Tab is delivered through the normal event path, so a keyboard event tap can catch and swallow it. Canned Web does this automatically while a site is sealed, along with Cmd-Q and Mission Control.

How do I disable Spotlight and screenshots for a kiosk?

Spotlight (Cmd-Space) and the screenshot tools (⌘⇧3/4/5) are dispatched from a privileged WindowServer path and never reach an app event tap, so a normal key blocker can’t stop them. The reliable way is to toggle their underlying “symbolic hotkeys” off, which is exactly what Canned Web does while sealed, and macOS restores them at logout.

Do I have to do this by hand for each shortcut?

No. You can chase individual shortcuts in System Settings and scripts, but macOS has no single switch that blocks them all, and it’s easy to miss one. Canned Web blocks the whole set, Spotlight, Cmd-Tab, Cmd-Q, Mission Control, screenshots and media keys, in one step when you seal a site.

Does blocking these shortcuts change my Mac permanently?

No. The changes apply only while a site is sealed and affect the live login session; macOS restores everything at logout, so a crash or reboot self-heals back to normal.

Is there a built-in macOS kiosk mode that does this?

No. Unlike iPadOS, macOS has no Guided Access or Single App Mode. Locking a Mac down means blocking the escapes yourself, or using a kiosk app that does it for you.