All comparisonsKarma Firewall and NetCageA small open-source Android firewall on F-Droid: pick the apps whose traffic you want blocked, with no IP or port rules to learn.Last checked 7 November 2026Check Karma Firewall’s own pageYou can’t install NetCage todayIt has no store listing and no public download, so there’s no install link on this page and no price to quote. If you need something on your phone now, Karma Firewall is there to install and NetCage isn’t.Better served by Karma FirewallChoose Karma Firewall if you want a tiny open-source app from F-Droid that holds no internet permission of its own.Better served by NetCageChoose NetCage if you want Wi-Fi and mobile rules, schedules, shareable Cage Packs and a foreground service that keeps the cage up after a reboot.Row by rowNetCage’s column comes from its code. Karma Firewall’s comes from the linked pages. “Not stated” means we didn’t find it there, not that it’s missing.

Feature

Karma Firewall

NetCage

Blocks one chosen app’s internet

Yes f-droid.org

Yes

Keeps blocking while the app is in the background

Not stated on the pages we checked

Yes

Needs no root

Not stated on the pages we checked

Yes

Open source

Yes f-droid.org

Shows ads

Not stated on the pages we checked

Partly. Promotions for the developer’s own apps only. No ad network.

In-app purchases

Not stated on the pages we checked

What it costs

App: Free. Free download from F-Droid, GitHub releases or the developer's site; the developer accepts a voluntary coffee donation f-droid.org

NetCage publishes no price.Where NetCage falls short

It takes Android’s one VPN slot. While NetCage is up you can’t run another VPN, and connecting one stops NetCage.

Apps that share an Android user ID are caged together, and there’s no way to separate them.

A caged app can still hand a link to a browser you haven’t caged, and that browser connects as normal.

It doesn’t work inside an app: no domain rules, no block lists, no traffic log. An app is caged or it isn’t.

Karma Firewall is open source and NetCage isn’t, so you can read one app’s code and not the other’s.

Every limit, in the documentationComing from Karma Firewall?The documentation has a page on how the two differ and which of its guides to read first. Read it on the documentation siteIf a row here is wrong, tell us and we’ll open the page again. Contact