Frequently Asked Questions
License & Registration
Please visit the Little Snitch Support pages and enter your email address to retrieve your lost license key. Little Snitch Support > Lost License
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…”
If you have a question or a problem related to your order, please contact our sales support team.
Delivering of the license key may take up to 15 minutes. Please also make sure the email is not in your spam folder. If you still did not receive the license key please contact our sales support team.
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.
A single license is valid for all your machines as long as you are the only user.
Of course! A family license is valid for up to five computers, used by people living in the same household.
The number of required seats is either the number of computers or the number of persons using these computers — whichever number is lower. For example, an office with five employees and eight computers would need a 5-seat license to use Little Snitch on all computers.
Yes, student discounts for Little Snitch are available at the Student App Centre website.
Assuming you’ve downloaded the Little Snitch Disk Image (.dmg file) to your Downloads folder, open a new Terminal window and enter the following command to verify the cryptographic signature of the downloaded file:
codesign --verify -R="anchor apple generic and certificate leaf[subject.OU] = MLZF7K7B5R" ~/Downloads/LittleSnitch*.dmg
If the result of this command is empty (no error message is shown), the file is intact and properly signed by Objective Development.
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.
Yes, your existing rules from Little Snitch 3 will be preserved.
Yes. Simply download and install Little Snitch 3 from our download page. Your rules and settings will be preserved.
Please visit our High Sierra Compatibility page for information about installing and running Little Snitch 4 on macOS High Sierra.
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/
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 restore your rule from that file via Little Snitch Configuration > File > Restore 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.
Open Little Snitch Configuration and choose File > Create Backup from the menu. This will create a backup file at the location of your choice. You can restore your rules from that file later via File > Restore from Backup.
By default, local network traffic is hidden in Little Snitch Network Monitor. If you want to see this traffic as well, you just have to enable “Show Local Network” in the Little Snitch Network Monitor menu.
This is a technical limitation of Apple Maps, the service that we are using for showing the map in Network Monitor. Apple’s Maps.app has the same limitation and doesn’t let you zoom out far enough to see a map of the whole world at once.
Open the Little Snitch Configuration application from your Applications folder, open Preferences > General and click the Stop button to turn off the Network Filter. Any network traffic will then be allowed, such as if Little Snitch wasn’t installed at all. If you are using the Little Snitch menu bar icon, you can also stop the filter by choosing “Stop Network Filter” from the menu.
Since version 3 Little Snitch can also handle and filter incoming connections. They are labeled with this icon:
No, sorry, this is currently not possible.
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.
Make sure to use a keyboard that’s directly connected to your computer (cable or Bluetooth). Changing the settings or entering the license key via any kind of remote access (e.g. Screen Sharing) will not work with the default security settings of Little Snitch.
You would need to change the order of your preferred languages in your macOS System Preferences > Language & Region settings and make sure that English is further up in the list than German. After a restart Little Snitch should then be localized in English.
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.
Whenever Little Snitch blocks a particular connection, this is indicated in realtime in Little Snitch Network Monitor by a red flashing of that connection. You can right-click on such a connection and choose “Show Corresponding Rule” from the context menu to open up Little Snitch Configuration and focus on the rule that’s responsible for this connection being denied.
At least one component of Little Snitch has not been updated correctly and most likely this is related to an issue with the kernel cache. As Little Snitch consists of multiple parts (including a kernel extension) it is necessary to update the kernel cache after the installation. Updating the kernel cache might reveal issues with third-party extensions. Please try to restart the system, run the Little Snitch Installer again. If the issue persists please generate a diagnostics report and contact 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.
To make sure you don’t miss any new versions that contain the latest bug fixes and improvements, you cannot disable these checks. This is critical because prerelease versions are not considered stable and still need testing before we’re confident in releasing them to all users.
If you want to downgrade from a prerelease version to the latest stable version, you can do so by downloading it from the website.
These instructions are outdated because only macOS 10.15.0 is affected. Install macOS 10.15.1 or later to fix the issue descibed here.
When you install Little Snitch on the initial version of macOS Catalina (version 10.15.0), you may get an error message “Little Snitch version mismatch detected” after restarting your Mac. This is due to a bug in the operating system.
Catalina sometimes refuses to perform the necessary boot cache update for the newly installed kernel extension. As a consequence, macOS still uses the previous version of the kernel extension from the outdated cache, which then results in a version conflict with all other updated components of Little Snitch.
Unfortunately it’s not possible to fix this problem in the Little Snitch Installer. macOS provides no means to repair such an invalid cache (except for some more elaborate actions in macOS Recovery). This problem can only be fixed by Apple with an update of macOS, so we are hoping that Apple will be able to address this issue soon.
In the meantime you can work around the problem by downgrading to the previously installed version of Little Snitch. It’s important to install the version that matches the currently installed kernel extension. To figure out which version has to be installed, please do the following:
1. Open Terminal
Open Terminal.app from your Applications > Utilities folder, type the following command and then press Return:
kextstat | grep obdev
2. Find the version number
You will see a result like this:
[...] at.obdev.nke.LittleSnitch (5422) [...]
The four-digit number in parentheses indicates the version of the currently installed kernel extension.
3. Downgrade Little Snitch
Download and install the corresponding Little Snitch version:
If your version is not listed here, please follow the instructions in this article instead.
Yes, Little Snitch 4.4 or newer is compatible with macOS 10.15 Catalina. Download Little Snitch
Yes, Little Snitch 4.2 or newer is compatible with macOS 10.14 Mojave and includes support for the new Dark Mode. Download Little Snitch
Yes, Little Snitch 3.7 or newer is compatible with macOS 10.12 Sierra. Download Little Snitch
Yes, Little Snitch 3.6 or newer is compatible with OS X 10.11.
Yes, Little Snitch 3.6 or newer is compatible with OS X 10.10.
Little Snitch 3.6.4 is the latest version compatible with OS X 10.9.
The download is available on this page.
Little Snitch 3.3.4 is the latest version compatible with OS X 10.8.
The download is available on this page.
Little Snitch 3.3.4 is the latest version compatible with OS X 10.7.
The download is available on this page.
Little Snitch 3.3.4 is the latest version compatible with OS X 10.6.
The download is available on this page.
Legacy versions of Little Snitch provide support back to OS X 10.2 Jaguar.
Downloads are available on this page.
Older versions of Little Snitch can be found on this page. Please try to use the most recent version of Little Snitch that supports your operating system.
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 order 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.
Unfortunately Apple’s regulations and submission guidelines do not allow applications like Little Snitch that operate on the system level on the iOS (iPhone, iPad, iPod touch), tvOS (Apple TV), or watchOS (Apple Watch) platforms.
Our entire team consists of longtime macOS developers and we love the Mac platform. It is therefore very unlikely that a version for a different platform will be available in the near future.
Only partially. The NVIDIA Web Drivers (as opposed to the original drivers provided by Apple) need to inject program code into running apps and Little Snitch (as some other apps like iBooks) do not allow that for security reasons. Therefore the Little Snitch Network Monitor can not show its inspector and map view.