Little Snitch Support

Little Snitch license keys can be distinguished by their first two characters:

• Little Snitch 4 license keys begin with “34…”
• Little Snitch 3 license keys begin with “33…”
• Little Snitch 2 license keys begin with “32…”

You can upgrade your existing Little Snitch license (version 2 or 3) to the latest version 4 at a reduced upgrade price.

If your license key begins with “34…”, your license is already valid for version 4 and no upgrade is required. If you don’t have your license key at hand, you can find it in Little Snitch Configuration > Preferences > Registration > Serial Number.

Assuming you’ve downloaded the Little Snitch Disk Image (.dmg file) to your Downloads folder, open a new Terminal window and type the following command:

If the result of this command is empty (no error message), the file is intact and properly signed.

However, if an error message is shown (like “not signed at all” or “failed to satisfy specified code requirement(s)”), this indicates that the file was maliciously modified and is no longer signed by Objective Development. In that case you should NOT open the disk image file.

As Little Snitch consists of multiple parts it is essential to run the Little Snitch Uninstaller to make sure all components are removed from your system. Little Snitch 3.4 or newer automatically starts the uninstaller as soon as you move the Little Snitch Configuration into your trash. For earlier versions please locate the installer in the following path /Library/Little Snitch/Little Snitch Uninstaller.app and start it manually.

The uninstaller lets you choose whether to remove or preserve user specific data (like rules and settings). If you want to remove those items manually, delete the following files and folders (the “~” tilde sign refers to your home folder):

• /Library/Application Support/Objective Development/Little Snitch/
• ~/Library/Application Support/Little Snitch/
• ~/Library/Preferences/at.obdev.LittleSnitchConfiguration.plist
• ~/Library/Preferences/at.obdev.LittleSnitchNetworkMonitor.plist
• ~/Library/Preferences/at.obdev.LittleSnitchInstaller.plist

Yes. Please retrieve one of the following files from your backup:

• Complete Ruleset: /Library/Application Support/Objective Development/Little Snitch/configuration.xpl
• User Specific Ruleset: ~/Library/Application Support/Little Snitch/configuration.user.xpl

You can then import the file via Little Snitch Configuration > Rules > Import from Backup.

Starting with macOS 10.12 Sierra it’s possible to arrange third-party menu bar icons via Command-drag (hold down the Command key and drag the item to the desired position).

In previous OS versions, third-party menu bar icons are at fixed positions and can’t be moved. Third-party tools like Bartender make it possible to arrange the items also in OS versions before 10.12 but for security reasons Little Snitch can not be used with such tools.

If you just want to save space in your menu bar you can simply turn off Little Snitch’s menu bar icon. The functions in it can also be accessed in the Little Snitch Configuration application’s preferences and you can open the Network Monitor window also via a configurable keyboard shortcut.

Since version 3 Little Snitch also can handles and filter incoming connections. They are labeled with this icon:

There are several possible causes for such behavior of Little Snitch.

First of all you really need to make sure that you have set the lifetime for the rule to “Forever“ when creating it (as opposed to “Once“, or “Until Quit“ etc.)

Then it’s also necessary that the path of the application (where it resides on your disk) remains unchanged. If you move an app to a different folder, the rules you created earlier for this app will cease to match.

Unfortunately the path of an application can also change without your explicit doing. If the path displayed in Little Snitch’s Network Alert contains parts like /private/var, it’s likely that the issue is related to the “Gatekeeper” functionality of macOS. See this blog post for further details.

Valid license keys for Little Snitch 4 start with “34…”, keys for version 3 start with “33…”. They are about 25 characters long.

When entering the license key, please copy and paste the key to avoid typos. If it still does not work, please contact our sales support team.

Little Snitch consists of multiple parts, some of them operating at a low level of the operating system, called the kernel. Little Snitch needs to trigger an update of kernel caches and requires a reboot during installation. Under rare circumstance this kernel cache update might fail, which may prevent your computer from starting.

If this happens during the installation of Little Snitch on your computer, please start it in safe mode by holding the Shift key (⇧) (you can find more information about safe mode here). If you are using OS X Yosemite or earlier, please repair your disk permissions using Disk Utilities.app (for detailed instructions see How & Why to repair disk permissions in OS X). As second step, start the Little Snitch Installer once again and perform a restart as instructed.

Usually this solves the issue. If you are still unable to start your computer, please get in touch with our tech support team.

In Little Snitch 3.7.2 we have improved protection against simulated keystrokes and mouse clicks to make sure that malicious software cannot change your firewall settings by simulating user interaction.

Unfortunately this also affects software that allows you to access your Mac remotely (like TeamViewer, RealVNC, etc).

If you do need remote access Little Snitch, you have to enable the “Allow GUI Scripting access to Little Snitch” option in Little Snitch Configuration > Preferences > Security.

Prey is installed under a separate user account (user: ‘prey’) on the system. In order to access its Little Snitch rules you have to open the Little Snitch Configuration as the user ‘prey’ by entering the following Terminal command (/Applications/Utilities/Terminal.app) and pressing Return:

sudo -u prey /Applications/Little\ Snitch\ Configuration.app/Contents/MacOS/Little\ Snitch\ Configuration

After entering your admin password when prompted, you should be able to see the Little Snitch Configuration window with one or more rule suggestion(s) for the Prey process named “node“ in the Suggestions > “Login Connections“ category. Select one of the rules and click on the “More“ button at the top right of the suggestions list. In the appearing popup menu choose “Allow any connection“. After closing the Little Snitch Configuration and restarting your system, all connections for Prey will be allowed.

Little Snitch cannot stall certain kinds of incoming connections or data. Please see Little Snitch help, chapter “Incoming connections” for more information.

Yes, Little Snitch 4.2 or newer is compatible with macOS 10.14 Mojave and includes support for the new Dark Mode.

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Yes, Little Snitch 4 and Little Snitch 3.8 are compatible with macOS 10.13 High Sierra.

• Download Little Snitch 4
• Download Little Snitch 3.8

Please also visit our High Sierra Compatibility page for information about installing and running Little Snitch on macOS High Sierra.

Yes, Little Snitch 3.7 or newer is compatible with macOS 10.12 Sierra.

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Yes, Little Snitch 3.6 or newer is compatible with OS X 10.11.

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Yes, Little Snitch 3.6 or newer is compatible with OS X 10.10.

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No, sorry. Little Snitch 3 already supports a range of eight major OS versions, starting with Mac OS X 10.6 Snow Leopard (released in 2009) up to macOS 10.13 High Sierra.

In oder to run Little Snitch on macOS Mojave, Little Snitch 4 is required. Owners of a version 3 license are eligible for a discounted upgrade to version 4.