How to Lock Messages on Mac

Lock Messages so it will not open without Touch ID or your password. Four steps, about a minute.

Lock Messages on Mac, step by step

Download Cloak from trycloak.app and open it. Set up Touch ID or a password the first time it asks. There is no account.
Click the plus button under Locked apps, tick Messages, and click Lock.
Quit Messages if it is open.
Open Messages again. Cloak now asks for Touch ID before it will launch.

Your Mac password works as a fallback by default. If other people know that password, open Cloak's Settings, turn off "Let my Mac password unlock Cloak", and set a Cloak password instead.

Who this is for

For anyone who shares a Mac with a partner, housemates or kids, or leaves a work laptop open on a desk. If someone else can sit at your Mac, they can read your Messages chats.

What Screen Time can't do

Apple has no way to lock a single app on a Mac. The closest thing is Screen Time, which puts a daily time limit on Messages. A limit is not a lock. Messages opens normally until the time runs out, the Screen Time passcode is four digits, and anyone who knows it can click Ignore Limit for the rest of the day. It was built to manage screen time, not privacy. Cloak asks for Touch ID or your password every single time Messages opens.

Why lock Messages at all

The Messages app shows every iMessage and SMS notification on your Mac, including two-factor codes and private texts from family. Because one glance at an open window can reveal a conversation that was never meant for anyone else, Messages is exactly the kind of app worth putting behind Touch ID.

Why a Mac-level lock beats Messages's own settings

Most messaging apps offer at best a screen-lock buried in settings that resets when you reopen the desktop client, and many offer nothing at all on macOS. A Mac-level lock from Cloak sits in front of the app every time it launches and cannot be skipped by simply quitting and reopening it.

Frequently asked questions

Does locking Messages with Cloak slow it down?

No. Cloak only steps in at launch to ask for Touch ID. Once Messages is unlocked it runs exactly as it normally would, with no background overhead.

Will I still get Messages notifications while it is locked?

Notification behaviour is controlled by macOS, not by Cloak. If you want Messages alerts hidden too, pair the lock with hiding the app, or turn off previews for Messages in System Settings under Notifications.

What happens if Touch ID is not available?

By default Cloak offers your Mac login password as a fallback, so you can still open Messages on a Mac without a Touch ID sensor or if your finger is not recognised. If other people know your Mac password, you can turn that fallback off and use a separate Cloak password instead.

Can I lock Messages with Screen Time instead?

Screen Time sets a time limit, not a lock. Messages opens normally until the limit is reached, and the limit can be ignored for the day by anyone who knows the four-digit passcode. Cloak asks for Touch ID every time.

How to lock Messages on your Mac