Leave a note on your locked Mac screen for whoever walks by

macOS can put a message on the lock screen: open System Settings, choose Lock Screen, turn on “Show message when locked” and set the text. It is one fixed message, though, kept in System Settings, and it is only seen when the lock screen is lit. For a note that changes through the day, such as “Back at 3:30” for whoever stops by your desk, a privacy screen that keeps the display awake, such as Shoji, does the job better.

Both have a place. The built-in message is right for things that never change, like how to return a lost laptop. A desk note is for the people around you today.

Setting a lock screen message in macOS

1. Open System Settings from the Apple menu.
2. Click Lock Screen in the sidebar.
3. Turn on “Show message when locked”.
4. Click Set, type your message and confirm it. macOS may ask for an administrator password.
5. Press Control-Command-Q to lock and check how it looks.

On older versions of macOS, the same option lives in System Preferences, under Security & Privacy, on the General tab.

The message is stored for the whole Mac, not for one user, and macOS shows it at the login window as well as on the lock screen. Keep that in mind when you choose what to write: everyone who sees your Mac locked, or sees it start up, sees this text.

What the built-in message is good for

Because it rarely changes, the built-in message suits information that should always be there:

• Return details for a lost Mac. A name and an email address you do not mind strangers having, so someone who finds the laptop can reach you without unlocking it.
• A work asset note. Some offices ask for a line naming the team or the help desk.
• A request. “Please do not unplug” on a Mac that runs long jobs overnight.

Leave out anything that helps someone guess your password, and anything you would not pin on a public notice board.

For day-to-day notes, the built-in message has three problems:

• Changing it is a trip to System Settings. Editing a note several times a day there gets old quickly, especially with an administrator password in the way.
• Nobody sees it on a dark screen. After you lock, the displays turn off soon after. Someone walking past sees a black screen unless they touch the keyboard or trackpad, which is the opposite of what you want from a note.
• It shares the screen with the login prompt. Your name, the password field and the message sit together, so it reads like a footnote rather than a sign.

Writing a note people actually read

A desk note is read in passing, from a step or two away. A few things make it useful:

• A time, not a duration. “Back at 3:30” tells people when to return. “Back soon” tells them nothing, because they do not know when you left.
• Where you are, if someone may need you. “In the design review” or “At lunch downstairs” saves a search.
• What to leave alone. “Export running, please leave it on” stops a helpful colleague from closing the lid.
• How to reach you. “Message me if it is urgent” points people somewhere other than your keyboard.

Keep it to one line. If it needs a second, it probably belongs in a message instead.

A note on a screen that stays awake

Shoji is a privacy screen for the Mac. Press Command-L and a screen slides shut over everything on every display. Its settings include a note on the lock, such as “Back at 3:30”, and a clock on the lock. Because it does not put the displays to sleep or shuffle your windows, the note is there for whoever walks by, and when you come back, Touch ID or your Mac password opens it with every window exactly where you left it.

A note says you are away, and some people will take that as an invitation. While the screen is shut, the keyboard belongs to the lock, so nothing anyone types reaches your apps. Each wrong password makes the next try wait longer, and you see every failed try when you come back, so you will know if someone did more than read the note. Outside an office, think twice before leaving one at all: in a cafe, “Back in ten minutes” tells a room of strangers how long the laptop will be alone.

Shoji is meant to work alongside the macOS lock, not replace it. After an away time you choose, it turns on the real macOS lock as well. That suits the two kinds of message neatly:

• The Shoji note covers short absences: meetings, lunch, a call in another room.
• The macOS message shows once the real lock takes over, and at the login window, so it is the place for return details on a lost Mac.

The note is text you set in Shoji’s settings, so it is only as accurate as you keep it. Update it when your plans change, or word it so it does not go stale, such as “In meetings this afternoon”.

Shoji costs $14 once, is free for 24 hours, and runs on macOS 14 or later, on Apple silicon and Intel. It needs no Screen Recording, Accessibility or Full Disk Access permission, and your password goes straight to macOS to check, never stored, logged or sent.

Questions

Why does my lock screen message not show? Check that “Show message when locked” is on in System Settings, under Lock Screen. Then lock with Control-Command-Q and wake the display. If the display has turned off, the message is there but you cannot see it until the screen lights up again.

Can the macOS message change on its own? Not with a built-in setting. macOS keeps it as a system-wide preference that only an administrator can change, so it is better suited to text that stays the same for months.

Will a note on the lock show my other windows? No. A note sits on the lock itself, and the lock covers every display. Your windows stay behind it until you unlock.