How to lock your Mac from the Terminal

The short answer

On current macOS the most reliable command-line ways to lock the screen are pmset displaysleepnow (which sleeps the display, locking the Mac if you require a password immediately), a Shortcuts action containing Lock Screen run with shortcuts run, or an osascript call that presses the built-in Control plus Command plus Q lock shortcut. The old CGSession -suspend command that many older answers still recommend has been removed and no longer exists on current macOS. Whichever method you choose, the screen only actually locks if "Require password after sleep or screen saver: immediately" is set in System Settings.

Method 1: pmset displaysleepnow

The simplest command needs nothing installed and no special permission:

pmset displaysleepnow

It puts the display to sleep immediately and does not require sudo. If your password requirement is set to immediately (covered at the end of this guide), the Mac is locked the instant the display sleeps. This is the same display-sleep primitive Peeku falls back on internally. The one thing to know is that it darkens the screen rather than showing the lock screen straight away: the Mac is still locked, you simply see a dark display until it is woken.

Method 2: a Shortcuts action, the cleanest modern way

The macOS Shortcuts app includes a first-party Lock Screen action, and the Shortcuts command-line tool can run it. Because it uses Apple's own action and triggers the real lock screen rather than display sleep, this tends to be the most predictable method across macOS versions.

Method 3: osascript pressing the lock shortcut

You can also have the system press the native lock shortcut for you:

osascript -e 'tell application "System Events" to keystroke "q" using {command down, control down}'

This sends Control plus Command plus Q, the built-in Lock Screen shortcut. Because it sends synthetic keystrokes through System Events, the app you run it from (Terminal, iTerm, or whatever calls it) needs Accessibility permission, which you grant in System Settings, then Privacy and Security, then Accessibility. If the command appears to do nothing, that missing permission is almost always the reason.

The command that no longer works

For years the most-copied answer was a path into a system menu bundle:

/System/Library/CoreServices/Menu Extras/User.menu/Contents/Resources/CGSession -suspend

On current macOS that file no longer exists, so the command simply fails. If you have pasted it from an old forum post and nothing happens, that is expected rather than a fault on your machine. Use one of the three methods above instead.

Bind it to one keystroke

The point of a command-line lock is usually to make locking effortless, so wire it to something you will actually reach for:

• A shell alias in your ~/.zshrc, for example alias lock='pmset displaysleepnow', then just type lock.
• A keyboard launcher such as Raycast or Alfred, set to run the command.
• A programmable key or a Stream Deck button mapped to the same command.

Any of these turns locking into a single action, which is a genuine improvement over reaching for a menu. The guide on every way to lock your Mac screen covers the keyboard shortcut, hot corners, and menu methods if you would rather not touch the Terminal at all.

The catch every command shares

A command-line lock is fast, but it is still manual. It only protects your Mac on the occasions you remember to run it, and the moments you most need it, stepping away mid-thought for a call or a coffee, are exactly the moments you are most likely to forget. This is the same gap behind a Mac that locks too aggressively while you are still reading or one that never locks when you leave: a fixed command, like a fixed timer, cannot tell whether you are actually at the desk. A keep-awake utility such as caffeinate running in the background makes this worse, because it can stop the timer-based lock from ever firing. If you are running caffeinate on purpose during a long job, you can still lock the screen without putting the Mac to sleep.

Locking automatically, with the same native primitives

Presence-based locking keeps the speed of a command but removes the need to remember it. This is the approach Peeku uses to lock the moment you walk away. It locks within seconds of you genuinely leaving, using three signals that all stay on your Mac:

• Face presence from the built-in camera, analysed locally with Apple's Vision framework. No image or video leaves the Mac, and it detects whether a face is present, not who it is.
• An optional Apple Watch proximity gate over Bluetooth, so it only locks when both the camera and the Watch agree you have gone.
• Keyboard and mouse idle time, so a short pause at the keyboard does not trigger it.

Under the hood it reaches for the same native macOS lock primitives a script would, the screen saver engine and display sleep among them, but it triggers them based on whether you are present rather than waiting for a keystroke. Two honest caveats carry over from the commands above. First, a lock is only secure if you set "Require password after sleep or screen saver: immediately" in System Settings, so set that first whichever method you use. Second, the full locking app ships free outside the Mac App Store, on Gumroad and as a notarised DMG, because the App Store sandbox blocks these same screen-lock calls. The two-minute setup guide and the overview of privacy-first, on-device locking cover the rest.

Quick reference

• pmset displaysleepnow: sleeps the display, which locks the Mac if a password is required immediately. No sudo, no extra permission.
• shortcuts run "Lock Screen": runs a Shortcuts Lock Screen action you have created. The cleanest modern method; confirm the name with shortcuts list.
• osascript sending Control plus Command plus Q: presses the native lock shortcut. Needs Accessibility permission for the calling app.
• CGSession -suspend: removed on current macOS. Do not rely on it.
• Every command is manual. Presence-based locking does the same job automatically the moment you actually walk away.