Remove app from quarantine — readme.mlav.land

Remove the macOS quarantine attribute from a downloaded app that Gatekeeper is blocking.

When you download an app from outside the Mac App Store, macOS tags it with a quarantine attribute. This triggers a Gatekeeper warning on first launch — or blocks the app from opening entirely with a message like "cannot be opened because the developer cannot be verified".

You can remove this attribute manually with a single terminal command.

Danger

Using this technique is appropriate when you trust the source of the app (official website, reputable developer) but macOS is blocking it purely because it was downloaded outside the App Store. It is not a workaround for running software from unknown or untrusted sources.

The command

sudo xattr -rd com.apple.quarantine /Applications/Feishin.app

Replace Feishin.app with the name of the app you want to unblock.

What each part does

Part	Meaning
`sudo`	Runs the command with admin privileges, required for apps in `/Applications`
`xattr`	macOS tool for reading and writing extended file attributes
`-r`	Recursive — applies to all files inside the app bundle
`-d`	Delete the specified attribute
`com.apple.quarantine`	The attribute macOS sets on downloaded files to flag them for Gatekeeper
`/Applications/Feishin.app`	Path to the app — update this for whatever app you're unblocking

Check if an app is quarantined

Before removing it, you can confirm the attribute is present:

xattr /Applications/Feishin.app

If com.apple.quarantine appears in the output, the app is quarantined.

Alternative: right-click to open

For a one-time bypass without using the terminal, right-click (or Control-click) the app in Finder and choose Open. macOS will show the warning but offer an Open button. This only works once — subsequent launches behave normally — but it's quicker if you'd rather avoid the terminal.