Download Copy Shelter

Copy Shelter on every platform

This page is for the Mac. Copy Shelter also runs on:

After it downloads

• Drag Copy Shelter into the Applications folder in the window that opens. This is not a formality: macOS runs an app opened from your Downloads folder out of a temporary read-only copy, and an app in that state cannot open at login, so scheduled backups would never run.
• Choose a folder to protect and somewhere to put the backup. A different disk from the one you are protecting, ideally, since one failure should not take both.
• Choose a passphrase. It is how you open the backup on another Mac, and we never see it.
• Keep the recovery key it shows you. It opens the backup if you forget the passphrase. Nobody, including us, can recover either. Somewhere that is not the Mac being backed up.

Where the backup can go

• An external drive or USB stick. Plug it in. Copy Shelter tells you by name when it is not connected.
• A NAS or network share. Any folder your Mac can see.
• iCloud Drive, Dropbox, Proton Drive, Google Drive. A folder in an account you already pay for, using space you already have.
• Several at once. Pro writes the same backup to more than one place, and checks each one separately.

Copy Shelter Restore

A separate free app that only puts files back. Point it at a backup, type your passphrase, choose which backup and where the files should go. It never changes the backup it reads.

It is worth having because of what it cannot do. It contains no code that knows how to back up or delete anything, nothing that checks whether you have paid, and nothing that makes a network request, so it works on a Mac with no connection and an account that has never purchased anything. Keep a copy beside your backup drive.

csctl, the command line tool

It reads a Copy Shelter backup with nothing but the drive and your passphrase, or the recovery key if you would rather. It comes as a disk image holding one file: open it and copy csctl anywhere. It needs no installation, and it is free whether or not you ever pay for anything. If the Mac that made the backup is gone, this is what gets your files back from any other Mac.

Its restore is the same algorithm described in the format specification, so it is also the reference an independent implementation can check itself against.

Already purchased Pro?

Open Copy Shelter, choose Sign In and give the address you purchased with. A six digit code arrives in that mailbox, and typing it back unlocks Pro. Do the same on any other Mac you own.

There is no license key to find or keep. The mailbox is what proves the purchase is yours, which is also why nothing you could lose can lock you out of it.

Common questions

Will macOS warn me about the download?

No. The app is signed with an Apple Developer ID, notarized by Apple, and the notarization ticket is stapled to the app itself, so Gatekeeper can check it without an internet connection. Double-click and it opens.

Does Copy Shelter need any permissions?

It asks macOS for access to the folders you choose to protect, the same prompt any app gets when it reads your Documents or Desktop. Nothing else.

How does Copy Shelter update?

It checks our update feed and offers you the new version. That request carries your current version and the usual information any web request carries. It is not tied to your license or your email, and there is no analytics of any kind. See the privacy policy.

Can I run Copy Shelter on more than one Mac?

Yes. Free is free on every Mac, and a Pro license covers the Macs you own.