This firewall app uses a dummy VPN to block unwanted traffic. Android requires you to authorise this app to use a VPN.

We do not monitor traffic. If you block an app we send the data to a dummy VPN which is effectively a black hole on your phone. The app will not even be able to establish a full network connection to try to send any private data. Data from blocked apps never leaves your phone. All traffic from allowed app is routed directly to the Internet without any monitoring, inspection, or interaction by Karma FW. Even if this Karma FW did monitor traffic (which it does not!), because Karma FW itself has NO Internet permissions, it cannot do anything with the data! Karma FW is the safest, most trusted Android Firewall.

A recent study found some VPN Firewalls can be dangerous, including popular ones. This is because they have the potential to inspect your app traffic. Karma FW is completely different from all other VPN Firewalls. Karma FW requires NO Internet permissions. Without permissions CANNOT send any data anywhere. We intercept no allowed traffic. The ONLY permission Karma FW requires is start on boot!

Karma FW is the safest, most trusted Android Firewall.

We do not require Internet permissions because of the unique way we handle traffic. If you allow an app, we simply tell Android to allow that app to use the Internet normally. Karma FW does not even get to see that traffic. Karma FW only gets to see blocked traffic, and we block this traffic at the connection phase, meaning we terminate the connection before any proper data is sent to Karma FW. Karma FW sees no personal data.

In fact without Internet permissions Karma FW itself cannot talk to the Internet at all. We do not collect any data about you or your phone. Many apps (even Firewalls that are supposed to protect you!) will often phone home sending your valuable data back to servers in Russia, China or America. We do not. No Internet permissions means our Karma FW cannot communicate anywhere. Karma FW is the safest, most trusted Android Firewall.

To start the firewall simply press the Red Key icon.

If the firewall starts successfully the Red Key icon will change to Green, and a small key icon will be shown in the notification bar at the top.

You are now protected.

To firewall an app and block its access to the Internet simply press the Green Go icon.

The icon will change to a Red No-entry icon.

The app will now be blocked from accessing the Internet.

To allow an app to access the Internet simply press the Red No-entry icon.

The icon will change to a Green Go icon.

The app can now access the Internet normally.

Yes, simply uncheck "Noticiations" from the main menu. We have tried to keep notification of blocked traffic to a minimum. Rather than cluttering up your notificaion bar with lots of notifications, we simply notify for the last blocked traffic. Simply click on the notification to open up the log viewer and see all blocked traffic.

Blocked app logs can always be opened from the main app GUI by selecting "View Logs"

Yes, Android traffic app counters are unaffected. Other Firewalls will show up in Android as all traffic coming from the firewall app itself! Karma FW does not. We maintain the integrity of Android traffic app stats.

You will not see the Karma FW app at the top of the Android traffic stats. Infact you will not see it in the traffic stats at all. Karma FW has no Internet Permissions and sends no data anywhere!

From Android 10 onwards third party apps (including Karma Firewall) can nolonger read /proc/net so we cannot see per app blocked traffic attempts. Don't worry the firewall still works on Android 10+ and blocks traffic.

We nolonger notify on blocked traffic, but blocked traffic is still logged, however there is no way for Karma Firewall to reconcile the blocked traffic we see with the blocked app:

Karma Firewall does not see any allowed traffic.

Blocked apps will still try to send data.

The firewall will block these connections, and show the date of the last attempt in red. A small amount of data that is sent to try build these network connections counts may count towards traffic stats shown by Android. This data goes nowhere. Note to save battery we only check blocked (and allowed) traffic stats periodically. Therefore there may be a small lag before any connection attempt is shown in the GUI or logs. This is normal.

If System apps share the same UID Karma FW will group these apps together. Clicking the app icon will exand the group to show all packages.

The reason we do this is because we have to firewall based on the UID. If apps share the same UID then they can only be blocked or allowed as a group. This usually only applies to system apps. System app groups vary from phone to phone. The example above shows Google services.

Yes, to see System Apps select "View System Apps" from the main menu:

Karma FW will now show System Apps:

Be careful blocking system apps. They may be required for essential tasks. If you do block a system app and find services on your phone stop to work, simply allow the System App again and all will be well.

No. This is a simple firewall, its designed to either allow or block an app from using the Internet. To implement IP address and port blocking we would need Internet Permissions, and have to inspect all traffic. This is not something we want to do. If you require this functionality try other firewalls on Google Play. But make sure you trust the authors, because they will have full access to all your Internet traffic!

Yes. Select "Allow Local" from the main menu and enter your local subnet.

As the text says if you do not know what you are doing, please do not use this option.

No. This is a simple firewall, its designed to either allow or block an app from using the Internet regardless of 2G, 3G, 4G, LTE or WiFi. Adding these extra features would complicate the GUI, require extra permissions, including traffic inspection, and is not a scenario that this app is targeted at.

Yes, select "Allow/Block All" from the main menu.

No. Any Android phone with Lollipop (Android 5) or above, can use this app.

Unfortunately an increasing number of mobile phone vendors are killing background apps to save battery and memory. This is a known issue that affects a lot of apps. Nokia phones despite being part of the Android One brand have really agressive background process killers.

If possible exclude Karma Firewall from any background app optimisations.

Also check that Karma filewall is set to always on VPN in Android:


If you select Copy Logs from the Logs Menu you can copy the logs to the clipboard and paster them into another app, such as email, text editor etc. Or use the Share Logs option.

Keeping Karma Firewall on Google Play became a real headache:

I wrote the app for myself, and released it in case others may find it useful. If you like Karma FW buy me a coffee with the link below:

Buy Steve a Coffee