How to Lock Signal on a Mac
Signal is built for private conversations, but on a Mac the desktop app stays open and signed in. If someone can touch your keyboard, they can read your chats.
Why people want to lock Signal
Signal protects messages in transit, and that is exactly why people use it for sensitive conversations. End-to-end encryption does nothing, though, once the desktop app is open on your screen. The weak point is the unlocked Mac, not the network.
What doesn’t fully work
Signal Desktop offers an optional Screen Lock that asks for your Mac’s login credentials, and it can hide message previews in notifications. Both are worth turning on. But Screen Lock depends on a timeout, and notification settings do nothing for the chats inside an open window.
Logging out of Signal Desktop between uses means linking the desktop app to your phone again each time, which is why almost nobody keeps doing it.
What actually works
Shoo! ends Signal’s process when you lock it and starts it again only after Touch ID, Apple Watch or your private backup password succeeds. There is no timeout window, and your Mac’s login password is never what unlocks it.
Shoo! only controls whether the Signal process runs. It never reads your messages or keys, and your linked-device setup stays as it was.
Try it free for 7 days — full functionality, no credit card, $17.99 once if you keep it.
Frequently asked
Can I lock Signal Desktop with Touch ID on a Mac?
Yes. With Shoo! Signal only opens after Touch ID succeeds, or after Apple Watch or a private backup password if your Mac has no Touch ID.
Does this replace Signal’s own Screen Lock?
No, they work together. Signal’s Screen Lock is a useful extra layer, while Shoo! makes sure the app is not running at all when you do not want it open.
Does Shoo! see my Signal messages?
No. Shoo! only controls whether the Signal app process is running. It never reads your chats, contacts or keys.
Will I have to link Signal to my phone again?
No. Signal keeps its own link to your phone, so unlocking it with Shoo! does not require setting it up again.