How to Enable Single App Mode in the Mac Dock

Single app mode turns every Dock click into a focus command: the app you clicked comes forward and every other app is hidden, instantly. No window shuffling, no visual noise — one app on screen at a time, enforced by the Dock itself. Apple has never put this in System Settings, but the hidden preference has worked for years and behaves identically on Ventura, Sonoma, and Sequoia.

Turn it on

Open Terminal from Applications → Utilities and run:

# make Dock clicks hide every other app
defaults write com.apple.dock single-app -bool true
killall Dock

killall Dock restarts the Dock process so it reads the new setting — the Dock blinks away and returns in about a second, with nothing else affected. From now on, clicking any app icon in the Dock hides all other apps as it switches.

Turn it off

# back to normal Dock behavior
defaults delete com.apple.dock single-app
killall Dock

Writing -bool false instead of deleting works too; deleting is tidier because it removes the key entirely, returning the Dock to its factory state for this setting.

What it changes — and what it doesn't

• Only Dock clicks trigger the hide-others behavior. Switching apps with Cmd+Tab, clicking a visible window, or opening apps from Spotlight behaves exactly as before — so you always have an escape hatch when you genuinely need two windows side by side.
• Hidden apps are hidden, not quit. Their windows come back exactly as they were when you click their Dock icon (which, in this mode, hides everything else in turn).
• Hidden apps keep running — downloads continue, music keeps playing.

That split is what makes the mode livable: the Dock becomes your “focus switcher” while the keyboard remains your “multitasking switcher.”

The manual equivalents, no Terminal required

If you want this occasionally rather than always, macOS has always had it as a modifier click:

• Option+Cmd+click a Dock icon — switch to that app and hide all others. Exactly what single-app mode automates.
• Option+click a Dock icon — switch to that app and hide only the one you were just using.
• Option+Cmd+H — hide everything except the current app, from the keyboard.

A good way to decide whether to commit: use Option+Cmd+click for a week. If you find you're holding the keys on every single Dock click, write the default and let the Dock do it for you.

Who this suits

Single app mode shines on small screens — a 13-inch MacBook where every visible window costs attention — and for anyone prone to rabbit-holing into whatever app happens to be peeking out from behind the current one. Writers, editors, and anyone doing deep work tend to keep it on permanently. It pairs naturally with hiding the Dock itself (Cmd+Option+D), leaving you a completely clean screen where the Dock appears only when summoned and every click from it produces a single-app workspace.

Living with it: two adjustments

A couple of habits change when everything hides on switch:

• Drag-and-drop between apps needs a different move, since the target app's window is hidden the moment you Dock-click away from it. Drag the file onto the target app's Dock icon instead — hold it there a beat and the app comes forward to receive the drop — or switch with Cmd+Tab, which doesn't trigger hiding.
• Reference-while-writing setups (a browser beside a document) are what Cmd+Tab and clicking visible windows are for. Single app mode never prevents two apps from being visible; it only makes the Dock enforce focus when you use it to switch.

To check later whether the mode is active, run defaults read com.apple.dock single-app — 1 means on, an error means the key was never set.

Make hidden apps visible at a glance

Once lots of apps are hidden, it helps to see which ones — the Dock can render hidden apps translucent. See how to dim hidden apps in the Dock; the two tweaks are made for each other.