Redoubt

Frequently asked questions

Short answers. The long ones are linked.

Is this LibreWolf?

No. Redoubt is an independent fork of LibreWolf’s source, maintained by one person who is not a LibreWolf developer. It ships LibreWolf’s privacy configuration and shared patch set on Android, under MPL-2.0. The LibreWolf project has not built, reviewed or endorsed it, so please report Redoubt problems to Redoubt, not to LibreWolf.

Why not IronFox?

If you want a mature, widely used hardened Firefox for Android, IronFox is that, and it is the browser LibreWolf itself recommends to Android users. Redoubt is for people who want LibreWolf’s own configuration on Android, measured row by row against LibreWolf desktop in PARITY.md, and Sync with LibreWolf desktop. The comparison, including where IronFox is ahead: POSITIONING.md.

How is Redoubt made?

One maintainer. AI coding agents (Claude Code, Codex and local models) write and check most of the code, patches, tests and documentation, run the gates (the build, the Fenix unit-test suite and emulator acceptance) and record the evidence. The maintainer sets direction, decides the trade-offs, tests on devices and signs releases. What you can check yourself is on the home page.

Who maintains it, and what if they stop?

One person, CPlusPlus17 on GitHub. If maintenance stops, the update check and the F-Droid repository simply stop announcing new versions. Your install keeps working but stops getting security fixes, so switch browsers then; IronFox is the established alternative.

How fast do security fixes ship?

There is no guaranteed turnaround. A release watch notifies the maintainer of every Firefox release and Mozilla security advisory. So far: Firefox 158.0 (2026-10-13) → Redoubt 158.0-1 the next day; Firefox 157.0.1 (2026-10-06) → Redoubt 157.0.1-1 on 2026-10-10. Only the latest release receives fixes.

Where is the signing key?

With one holder, the maintainer. Today the release key and the update-signing key are passphrase-encrypted files on the maintainer’s workstation, not on an offline machine; offline backups exist. Moving the keys to a hardware key (a YubiKey, with a touch for every signature) is planned. CI builds the APKs on another machine and never has a key. Details: SIGNING.md.

Is it on Google Play or f-droid.org?

No: Redoubt is on its own F-Droid repository and GitHub Releases. Its release key is never uploaded to Google; if Redoubt is ever on Google Play, it will use a separate Play-only key, and a Play install and a GitHub or F-Droid install will then not be able to update each other. f-droid.org can publish developer-signed APKs only if it reproduces the build bit for bit, and Redoubt’s build is not reproduced across machines yet.

Is the update check a beacon?

It is off by default. If you turn it on, the app fetches a small signed file from redoubtbrowser.org at most once a day while it is open, with no identifier, not even the app version. GitHub, which hosts the site, sees your IP address and the time. When F-Droid installed the app, the switch is hidden: F-Droid tells you about updates.

Does it have telemetry?

No. The Glean upload path, Adjust, Nimbus experiments, crash-report upload and Google Play services are removed. By default the app still contacts Mozilla’s Remote Settings (blocklists, certificate revocation data) and addons.mozilla.org (add-on updates), and uBlock Origin fetches its filter lists; the privacy policy lists what each request contains.

Can I install extensions?

Yes, from addons.mozilla.org, as in Firefox for Android. uBlock Origin is preinstalled.

Do push notifications from websites work?

No. Firebase Cloud Messaging is removed with Google Play services, so websites cannot send push notifications, and a tab sent from another device arrives at the next sync rather than at once.

Is the JavaScript JIT on?

Yes, as in Firefox and LibreWolf desktop; Redoubt does not change it. IronFox turns it off by default, trading speed for a smaller attack surface.

A site breaks. What can I try?

How much memory does it use?

Not measured on low-RAM phones yet. Site isolation runs more processes than stock Firefox for Android, and that costs memory. With about 15 tabs open, Redoubt used about 2 GB on a Pixel 9a and about 1.3 GB on a Xiaomi Mi 8 in a test on 2026-10-14. Reports from phones with 4 GB of RAM or less are welcome.

Known issues

Reddit’s login page stays blank. reddit.com/login shows a white page in Redoubt, on a fresh profile and after visiting reddit.com; reading Reddit works. Turning off tracking protection for the site, allowing WebGL, turning off resist-fingerprinting or uBlock Origin, or requesting the desktop site did not fix it in our tests. Under investigation. The rest of the list is on the home page.

Are the builds reproducible?

Not yet. Rebuilding the APK on the same machine gave byte-identical APKs (checked on a beta built from Firefox ESR 153); Gecko itself and builds on a second machine are not verified. Every release names its source commit and the SHA-256 of Mozilla’s source tarball. Details: REPRODUCIBLE.md.

How do I report a security issue?

Privately, by e-mail to security@redoubtbrowser.org (no GitHub account needed) or through GitHub private vulnerability reporting. Please do not open a public issue for it. More on the Security page.