Mainspring › Mainspring Guides › Lock-screen message
Mac settings with their own controls
Add a lock-screen message: “If found, call…”
In the appBrowse all›Privacy›Lock-screen message
If your Mac is ever lost, a short message on the lock screen gives an honest finder a way to reach you. Mainspring sets it in a few seconds.
Set a message
- Open Browse all and pick the Privacy chip.
- On Lock-screen message — “Show an ‘if found’ note on the login and lock screen.” — click Set….
- Type your message — the box suggests If found, call +1 555 0123.
- Click Save or press Return.
The card now shows your message in quotes, and macOS shows it on the login window and lock screen.
Change or clear it
- Edit opens the message for changes; Cancel closes it without saving.
- Clear removes the message.
The rules
- Up to 120 characters, on one line. Longer, and a banner says “Keep it to 120 characters or fewer.”
- No straight double quotes (
"), backslashes (\), backticks (`) or dollar signs ($). Use one, and the banner says “Quotes, backslashes, backticks and $ aren't allowed.” Curly quotes are fine. - Save stays grey until you've typed something.
Why it may ask for a password
The message is a system-wide setting, stored in
/Library/Preferences/com.apple.loginwindow, so changing it needs administrator rights.
With the helper Mainspring's installer sets up, there's no prompt; without it, macOS asks for your
password, as the card notes. Cancelling leaves the message unchanged.
Anyone who picks up your Mac can read the message, so keep it to what a finder
needs: a phone number or email address that isn't on the Mac itself.
Try it yourself
Everything in this guide is in Mainspring's free trial — no account needed, and every change can be undone in one click.
Try Mainspring free →Signed & notarized by Apple · 1-day free trial · $29 once
