Redoubt Android 158.0-1 — Beta 1

Important

This is a prerelease, built from Firefox 158.0b4, which is Mozilla's beta source. Firefox 158.0 is scheduled for 2026-10-09. Redoubt 158.0-1, built from the final 158.0 source, will follow it and installs over this beta as an update. Redoubt 157.0-3 is still the current stable release. Install this beta only if you want to try Firefox 158 early and can live with beta bugs.

First beta of Redoubt for Android on Firefox 158. It installs over 157.0-3 as an update and keeps your settings. Requires Android 8.0 or later.

Redoubt is an independent project. It is not affiliated with or endorsed by LibreWolf or Mozilla. Website: https://redoubtbrowser.org

How you get it, and how you leave it

• The in-app update check will not offer this beta. It only announces stable releases, so 157.0-3 installs keep saying they are up to date. To try the beta, download it from this page.
• Obtainium: prereleases are offered only if Include prereleases is on for this app.
• Back to stable: 158.0-1 installs over this beta as a normal update. Going back to 157.0-3 is not possible without uninstalling first, which deletes your data, because Android does not install a lower version over a higher one.
• Version shown in About: 158.0b4-1. The final release will show 158.0-1.

What's new since 157.0-3

Firefox 158. The engine moves from Firefox 157 to the 158 beta (158.0b4), with its fixes and changes. Redoubt's patches and privacy configuration carry over; the packaged librewolf.cfg is byte-identical to 157.0-3's.

Password managers can fill Reddit-style login forms. Some sites, reddit.com/login among them, put their username and password fields inside page components (open shadow roots). Android autofill services got no fill request when you tapped such a field. They now get one (tested with a test autofill service; no individual password manager has been tested yet). Only login fields count: a form needs a password field. A newsletter or checkout email field inside a component still does not trigger a request, as in Firefox. Fields inside closed components are still not reachable.

"Delete browsing data on quit" now also works when the app is swiped away, killed or crashes. Before, it ran only when you chose Quit in the menu. Now:

• if the last session did not end with Quit, the next start deletes the data types you selected before any tab, link, custom tab or shortcut loads a page;
• swiping the app away from recent apps also starts the deletion right away, when no other Redoubt window (a custom tab or an installed web app) is still open.

What this means for you: with Cookies selected, any exit other than Quit now logs you out of every site: a swipe-away, Android stopping the app in the background, a crash, or a phone restart. That is what the setting promises, but before this release it often did not happen.

The guarantee is bounded. If the engine has not confirmed the deletion 20 seconds after it started, the start continues anyway (so the browser cannot hang) and the deletion is tried again after the next exit that is not Quit. If the app dies during the deletion itself three starts in a row, the next start skips it, so a deletion that keeps failing cannot lock you out of the browser. Not held back by the deletion: uBlock Origin's filter-list updates, and a pre-connect (no request, no cookie) that an app opening a custom tab may ask for. With Browsing history selected, restored tabs also lose their back/forward list.

Switching uBlock Origin off right after start no longer pauses browsing. If you disabled uBO in Settings → Add-ons while the browser was still starting, pages could stay paused until the start-up wait gave up, with a "startup failed" message. Redoubt now sees that you switched uBO off and lets pages load (unfiltered, as you asked) right away.

Everything else carries over from 157.0-3: uBlock Origin 1.75.0 with the cookie-notice lists on by default, H.264/AAC video playback, the opt-in update check without Accept-Language and hidden on store installs, and the same signing key.

Verify what you downloaded

sha256sum -c SHA256SUMS.signed
apksigner verify --print-certs fenix-<abi>-release.apk | grep -i SHA-256

The certificate digest must be:

64:14:EB:33:46:81:CF:6E:92:90:34:B5:6A:06:2D:2B:8D:A0:90:82:21:72:F7:A3:95:2C:85:FD:D1:28:3B:D0

Signed with APK signature schemes v2 and v3, no v1, using the same key as 157.0-3 and every earlier release.

Which file

• fenix-arm64-v8a-release.apk: almost any phone from the last several years.
• armeabi-v7a: older 32-bit devices.
• x86_64: emulators.
• The universal APK carries all three and is much larger.

Known limitations

These are stated plainly; see docs/android/PARITY.md.

• Beta source: Firefox 158.0b4 is not the final 158.0. Mozilla may still change things before 2026-10-09, and 158.0-1 will be rebuilt from the final source.
• Device testing: automated device testing ran on an x86_64 emulator (Android 14). The ARM builds were checked but not run on a physical phone. Reports from real devices are welcome.
• Autofill: tested only with a test autofill service, test pages and reddit.com/login; no individual password manager (Proton Pass, Bitwarden, KeePassDX…) has been tested yet. On a fresh profile, opening reddit.com/login directly can stay blank (as in 157); open reddit.com first.
• No content-process sandbox on Android: Gecko's content sandbox does not exist on Android, and Android's isolated processes are not used (they break H.264/AAC video; see the 157.0-3 notes). Redoubt ships the same privacy configuration and Gecko security patches as LibreWolf desktop, on a platform with weaker process containment.
• DNS over HTTPS: DoH configuration from preferences doesn't apply. Use the DoH screen in Settings.
• Signing key: one person holds the signing key.

Provenance

• Source: built from 6d146b418962b95631bd4f6da3d9cdbac65b081e (branch android/158-beta1) against Firefox 158.0b4 (firefox-158.0b4.source.tar.xz, sha256 6e8c17884180287eb31269bd7ada0b6c92440434caa285986101835373e2111a, signature checked against Mozilla's release key).
• Build: CI run 37576802707, with MOZ_BUILD_DATE 20261007050000; versionCodes 2016188904-2016188911.
• Signing: signed by the maintainer; CI never sees the key.
• Evidence: docs/android/evidence/lw-m7-01/release-158.0-1-beta.1/, docs/android/evidence/lw-m7-42/, lw-m7-44/ and lw-m7-45/.

Redoubt 157.0-3

Redoubt 157.0-3 fixes video playback. In 157.0-2, most web video did not play: anything encoded as H.264 video or AAC audio, which covers most sites. That includes plain MP4 files and the streaming players most video sites use. This hotfix makes them play again. It installs over 157.0-2 as an update and keeps your settings. Requires Android 8.0 or later.

Redoubt is an independent project. It is not affiliated with or endorsed by LibreWolf or Mozilla. Website: https://redoubtbrowser.org

What's new since 157.0-2

Videos play again. H.264 and AAC media now decode, both as plain video files and through the streaming players most sites use (Media Source Extensions). 157.0-2 played only VP8, VP9 and AV1 video with Opus audio.

A security trade-off, stated plainly: web content no longer runs in Android "isolated" processes. 157.0-2 ran web pages in Android isolated processes. This was a Redoubt change; stock Firefox for Android does not do it. In Firefox 157, a page running in an isolated process cannot use Android's video decoders, so nothing can play H.264 or AAC. This is a known upstream bug, Mozilla bug 1810736, and no setting works around it. Redoubt 157.0-3 runs web content the way Firefox for Android does.

• What this costs: web content processes now run under the app's own Android user. A content process taken over by a browser exploit could therefore read the app's own data (profile, cookies, saved logins). This is the same as in Firefox for Android.
• What is unchanged: Fission site isolation for high-value sites (locked on) and RLBox library sandboxing.
• What comes next: isolation will be turned back on once a Firefox release can decode video inside an isolated process.

Update check: no language header. The opt-in update check no longer sends an Accept-Language header, so the request no longer reveals your language. It still carries no identifier and no version.

Update check hidden on store installs. If an app store installed Redoubt (an F-Droid client, Accrescent or Google Play), the Check for updates setting is hidden and nothing is sent, because the store notifies you. Installs from this page are not affected.

Everything else carries over from 157.0-2: Firefox 157 with its Android security fixes, uBlock Origin 1.75.0 with the cookie-notice lists on by default, the same privacy configuration, and the same signing key.

Verify what you downloaded

sha256sum -c SHA256SUMS.signed
apksigner verify --print-certs fenix-<abi>-release.apk | grep -i SHA-256

The certificate digest must be:

64:14:EB:33:46:81:CF:6E:92:90:34:B5:6A:06:2D:2B:8D:A0:90:82:21:72:F7:A3:95:2C:85:FD:D1:28:3B:D0

Signed with APK signature schemes v2 and v3, no v1, using the same key as 157.0-2 and every beta.

Which file

• fenix-arm64-v8a-release.apk: almost any phone from the last several years.
• armeabi-v7a: older 32-bit devices.
• x86_64: emulators.
• The universal APK carries all three and is much larger.

Updates: use the in-app check, Obtainium with this repository, or watch the Releases page.

Known limitations

These are stated plainly; see docs/android/PARITY.md.

• Device testing: automated device testing ran on an x86_64 emulator. Real-device feedback comes from early adopters like you, and reports are welcome.
• No content-process sandbox on Android: Gecko's content sandbox does not exist on Android. As of this release, Android's isolated processes are not used either (see above). Redoubt ships the same privacy configuration and Gecko security patches as LibreWolf desktop, on a platform with weaker process containment.
• DNS over HTTPS: DoH configuration from preferences doesn't apply. Use the DoH screen in Settings.
• Signing key: one person holds the signing key.

Provenance

• Source: built from 19f866ea81aee14352b1c041108eb180b47f4848 against Firefox 157.0.
• Build: CI run 37441476096, with MOZ_BUILD_DATE 20261006090000.
• Signing: signed by the maintainer; CI never sees the key.
• Evidence: docs/android/evidence/lw-m7-01/release-157.0-3/ and docs/android/evidence/video-playback/.

Redoubt 157.0-2

Redoubt 157.0-2 is the first stable release of Redoubt for Android: a privacy-hardened browser built on Firefox 157 with LibreWolf's privacy configuration. It installs over any Redoubt beta as an update and keeps your settings. Requires Android 8.0 or later.

Redoubt is an independent project. It is not affiliated with or endorsed by LibreWolf or Mozilla. Website: https://redoubtbrowser.org

What's new since Beta 5

In-app update check (opt-in, off by default). Settings → Check for updates. When you turn it on, Redoubt asks redoubtbrowser.org at most once a day whether a newer version exists, and shows a notice with a link if there is one. It never downloads or installs anything by itself. The request carries no identifier, not even your version, and every answer must be signed with Redoubt's update key, or it is ignored. The site is hosted on GitHub Pages, so GitHub sees your IP address and the time of the request.

Release builds come from CI. This release was built by Redoubt's CI on a dedicated build machine, then signed by the maintainer.

Everything from the betas carries over:

• Firefox 157, with Firefox 157's Android security fixes.
• uBlock Origin 1.75.0, with the cookie-notice filter lists on by default.
• AI page summaries, IP Protection, Google Lens and Merino shortcut icons switched off.
• Local-network and storage-access protections kept strict.

Verify what you downloaded

sha256sum -c SHA256SUMS.signed
apksigner verify --print-certs fenix-<abi>-release.apk | grep -i SHA-256

The certificate digest must be:

64:14:EB:33:46:81:CF:6E:92:90:34:B5:6A:06:2D:2B:8D:A0:90:82:21:72:F7:A3:95:2C:85:FD:D1:28:3B:D0

Signed with APK signature schemes v2 and v3, no v1, using the same key as every beta.

Which file

• fenix-arm64-v8a-release.apk: almost any phone from the last several years.
• armeabi-v7a: older 32-bit devices.
• x86_64: emulators.
• The universal APK carries all three and is much larger.

Updates: use the in-app check, Obtainium with this repository, or watch the Releases page.

Known limitations

These are stated plainly; see docs/android/PARITY.md.

• Device testing: automated device testing ran on an x86_64 emulator. Real-device feedback comes from early adopters like you, and reports are welcome.
• No content-process sandbox on Android: Redoubt ships the same privacy configuration and Gecko security patches as LibreWolf desktop, on a platform with weaker process containment.
• DNS over HTTPS: DoH configuration from preferences doesn't apply. Use the DoH screen in Settings.
• Signing key: one person holds the signing key.

Provenance

• Source: built from 27240eb6d0140704f637135c7985c778a9f46e51 against Firefox 157.0.
• Build: CI run 37248744119, with MOZ_BUILD_DATE 20261005000000.
• Signing: signed by the maintainer; CI never sees the key.
• Evidence: docs/android/evidence/lw-m7-01/release-157.0-2/.

Redoubt Android 157.0-1 — Beta 5 (superseded by 157.0-2)

Warning

Superseded by Redoubt 157.0-2, the first stable release. Please install it instead. It updates Beta 5 in place and keeps your settings. It also adds an opt-in in-app update check (Settings → Check for updates), so after this one install you can be told about future releases.

Fifth beta of Redoubt for Android, on Firefox 157. It installs over Beta 4 as an update and keeps your settings. Requires Android 8.0 or later. This is a prerelease.

What changed since Beta 4

Cookie-notice lists for everyone. Beta 4 switched on uBlock Origin's "EasyList/uBO – Cookie Notices" lists only for fresh installs that were online on first launch. Beta 5 also switches them on, once, for:

• profiles updated from Beta 3 or earlier;
• installs whose first launch was offline.

After that, your choice is kept. If you switch the lists off in uBO → Filter lists, they stay off across restarts and updates.

One exception: if you already had these lists in Beta 4 and switched both of them off, Beta 5 turns them on one more time. Switch them off again and they stay off. uBO's saved settings can't tell "switched off" apart from "never had them".

Version shown in About. The app still shows 157.0-1, the same as Beta 4. The internal version number is higher, so the update installs normally. The release tag tells the builds apart.

Everything else is unchanged from Beta 4: the Firefox 157 engine, the disabled 157 cloud features (Shake to Summarize, IP Protection, Merino shortcut icons, Google Lens), and the fixes for the default-browser prompt, add-on state and WebGL/canvas permissions.

Verify what you downloaded

sha256sum -c SHA256SUMS.signed
apksigner verify --print-certs fenix-<abi>-release.apk | grep -i SHA-256

The certificate digest must be:

64:14:EB:33:46:81:CF:6E:92:90:34:B5:6A:06:2D:2B:8D:A0:90:82:21:72:F7:A3:95:2C:85:FD:D1:28:3B:D0

The APKs are signed with APK signature schemes v2 and v3 (no v1), using the same key as earlier betas.

Which file

• fenix-arm64-v8a-release.apk: almost any phone from the last several years.
• armeabi-v7a: older 32-bit devices.
• x86_64: emulators.
• The universal APK carries all three and is much larger, so prefer a per-ABI build.

Known limitations

• Testing coverage: the automated on-device tests ran on an x86_64 emulator only. The ARM builds were checked but not run on a physical phone. Reports from real devices are welcome.
• Release cadence: Redoubt follows Firefox's regular releases, so expect frequent updates.
• Process sandbox: Android has no content-process sandbox. Redoubt ships the same privacy configuration and Gecko security patches as LibreWolf desktop, on a platform with weaker process containment (see docs/android/PARITY.md).
• DNS over HTTPS: DoH settings from preferences don't apply. Use the DoH screen in Settings.
• First-run network traffic: first run contacts Remote Settings, uBlock Origin's filter-list hosts, and GitHub for Redoubt's pinned uBO list catalog. Nothing telemetry-, ads- or crash-reporting-shaped is contacted.
• Signing key: one person holds the signing key.

Provenance

Built from cdeadd6cebed214a05085899930d7dd269fa5a5a against Firefox 157.0. Three ABIs come from one fat AAR, with R8 on. Signed by the maintainer; CI never sees the key. The evidence is in docs/android/evidence/lw-m7-41/migration/ and docs/android/evidence/lw-m7-01/release-157.0/beta5/.

Redoubt Android 157.0-1 — Beta 4 (superseded by Beta 5)

Warning

Superseded by Beta 5. Please install Beta 5 instead. It updates Beta 4 in place and keeps your settings. It also switches on uBlock Origin's cookie-notice lists once for profiles that didn't get them: updates from Beta 3, and installs whose first launch was offline.

Fourth beta of Redoubt for Android, and the first built on Firefox 157. Redoubt for Android now follows Firefox's regular releases instead of ESR, so new Gecko versions and Firefox for Android's security fixes arrive with each release. It installs over Beta 3 as an update and keeps your settings. Requires Android 8.0 or later. This is a prerelease.

What changed since Beta 3

Firefox 157. The engine and app move from Firefox ESR 153.4 to Firefox 157.0. That brings four major versions of fixes and features, including Android-only security fixes that ESR never received.

Cookie banners are handled by uBlock Origin. Firefox 156 removed its built-in cookie-banner service, and Beta 3's cookie-banner settings went with it. Fresh installs of Beta 4 now get uBlock Origin's "EasyList/uBO – Cookie Notices" filter lists switched on, and you can switch them off in uBO's Filter lists pane.

• If you're updating from Beta 3: turn them on yourself in uBO → Filter lists → Cookie notices. uBO only applies Redoubt's default list selection on its very first run, and the same applies if your first launch was offline.
• How it differs: filter lists hide or block banners. They don't click "Reject".

New Firefox 157 cloud features are switched off. Firefox 157 turns on several features that send data to Mozilla or Google. Redoubt switches off:

• Shake to Summarize: AI page summaries through Mozilla's LLM service.
• IP Protection: Mozilla's VPN, with its setup prompt and its start at launch.
• Shortcut icons: "Add shortcut" icons fetched from Mozilla's Merino servers.
• Google Lens: Lens image upload.

Fixed

• Default-browser prompt: Android's "Set Redoubt as your default browser?" dialog no longer appears on the fourth cold start. Beta 3 also has this bug.
• Add-on re-enable: re-enabling a disabled extension now starts it right away, instead of after a restart. Betas 2 and 3 also have this bug.
• Add-on disable at install: a "disable" choice made while installing an extension is no longer overwritten.
• WebGL and canvas permissions list: it no longer opens empty after a restart.

Unchanged: local-network protection for top-level navigations stays on, as in every beta, and uBlock Origin is still 1.75.0.

Verify what you downloaded

sha256sum -c SHA256SUMS.signed
apksigner verify --print-certs fenix-<abi>-release.apk | grep -i SHA-256

The certificate digest must be:

64:14:EB:33:46:81:CF:6E:92:90:34:B5:6A:06:2D:2B:8D:A0:90:82:21:72:F7:A3:95:2C:85:FD:D1:28:3B:D0

Signed with APK signature schemes v2 and v3, no v1, with the same key as earlier betas.

Which file

fenix-arm64-v8a-release.apk suits almost any phone from the last several years. Use armeabi-v7a for older 32-bit devices and x86_64 for emulators. The universal APK carries all three and is much larger, so prefer a per-ABI build.

Known limitations

• Testing coverage: the automated on-device tests ran on an x86_64 emulator only. The ARM builds contain the same app with ARM engines and were checked, but not run on a physical phone. Reports from real devices are especially welcome.
• Faster release cadence: Redoubt now follows Firefox releases, so expect more frequent updates.
• No content-process sandbox on Android: Redoubt ships the same privacy configuration and Gecko security patches as LibreWolf desktop, on a platform with weaker process containment. docs/android/PARITY.md says exactly where.
• DNS over HTTPS: DoH configuration from preferences doesn't apply. Use the DoH screen in Settings.
• First-run network traffic: the first run contacts Remote Settings (revocation, blocklists, tracking-protection lists), uBlock Origin's filter-list hosts, and GitHub for Redoubt's pinned uBO list catalog. Nothing telemetry-, ads- or crash-reporting-shaped is contacted.
• Single signing key: one person holds the signing key. If it is lost, this applicationId can no longer be updated.

Provenance

Built from 6202ee6d16bdc5cf9d9f2df4b5c311817fce1a8c against Firefox 157.0. Three ABIs come from one fat AAR, with R8 on. Signed by the maintainer; CI never sees the key. The evidence is in docs/android/evidence/lw-m7-01/release-157.0/.

Redoubt Android 153.4.0esr-1 — Beta 3 (superseded by Beta 4)

Warning

Superseded by Beta 4. Please install Beta 4 instead. It updates Beta 3 in place and keeps your settings.

Beta 4 moves to Firefox 157 and fixes three problems Beta 3 has:

• Android's "set as default browser" prompt appears on the fourth cold start.
• A re-enabled extension doesn't start until you restart.
• An extension's "disable" choice made at install time can be overwritten.

Third beta of Redoubt for Android, now built on Firefox ESR 153.4 (from 153.0) with LibreWolf's patch set. It installs over Beta 2 as an update, and settings are kept. Requires Android 8.0 or later. This is a prerelease.

What changed since Beta 2

Security updates. Gecko moves from 153.0esr to 153.4.0esr, which includes Mozilla's ESR security advisories MFSA 2026-77, 2026-85, 2026-93 and 2026-100.

"uBlock Origin setup failed" is fixed. Beta 2 showed it in two situations:

• Fresh install: uBlock Origin updated itself from addons.mozilla.org during first-run setup, and the setup check failed.
• Launch from the home screen: opening the app from the launcher, without a link, showed the same dialog after 30 seconds.

Both are fixed. uBlock Origin is now pinned at 1.75.0.

Mullvad DNS over HTTPS is going away. Mullvad is discontinuing its DoH service, so it has been removed from the provider list. If you had selected Mullvad, Redoubt moves you to the default provider (Quad9) once, keeps your protection level, and tells you about the change.

about:config works again. In Gecko 153.4 the page showed only a spinner. It now uses Firefox's own fix and still runs under the stricter security policy.

Smaller changes

• "What's new" and release notes now point to this project's releases page.
• The disk cache stays off, and if Gecko ever writes one, it is now encrypted.
• uBlock Origin downloads its filter-list bootstrap from librewolf.dev.

Verify what you downloaded

sha256sum -c SHA256SUMS.signed
apksigner verify --print-certs fenix-<abi>-release.apk | grep -i SHA-256

The certificate digest must be:

64:14:EB:33:46:81:CF:6E:92:90:34:B5:6A:06:2D:2B:8D:A0:90:82:21:72:F7:A3:95:2C:85:FD:D1:28:3B:D0

Signed with APK signature schemes v2 and v3, no v1. Same key as Beta 2.

Which file

fenix-arm64-v8a-release.apk works on almost any phone from the last several years. Use armeabi-v7a for older 32-bit devices and x86_64 for emulators. The universal APK carries all three and is much larger, so prefer a per-ABI build.

Known limitations

• Testing coverage: the automated on-device tests for this beta ran on an x86_64 emulator only. The ARM builds are byte-for-byte the same app with ARM engines; they were checked but not run on a physical phone. Reports from real devices are especially welcome.
• No content-process sandbox: the Gecko content-process sandbox is absent on Android. Redoubt ships the same privacy configuration and Gecko-level security patches as LibreWolf desktop, on a platform whose process containment is weaker. docs/android/PARITY.md says exactly where.
• Android-only security fixes: Firefox for Android has fixed some security issues that have no ESR counterpart yet. These are tracked openly and are not all backported.
• DNS-over-HTTPS configuration: DoH configuration from preferences does not apply. Use the DoH screen in Settings.
• First-run network requests: first run contacts Remote Settings (revocation, blocklists, tracking-protection lists) and uBlock Origin's filter-list hosts. Nothing telemetry-, ads- or crash-reporting-shaped is contacted.
• Single signing key: one person holds the signing key. If that key is lost, this applicationId can no longer be updated.

Provenance

Built from 0a134441b77a888f365e81da02beee71d6e3b9c4 against Firefox ESR 153.4.0. Three ABIs come from one fat AAR, with R8 on. Signed by the maintainer; CI never sees the key. The evidence is in docs/android/evidence/lw-m7-01/esr-153.4.0/.

Redoubt Android 153.0esr-1 — Beta 2 (superseded by Beta 3)

Warning

Superseded by Beta 3. Please install Beta 3 instead; it updates Beta 2 in place and keeps your settings.

Beta 2 has two known problems that Beta 3 fixes. It also lacks the Firefox ESR 153.4 security updates.

• "uBlock Origin setup failed" appears on fresh installs.
• The same dialog appears 30 seconds after opening the app from the home screen.

If you selected Mullvad for DNS over HTTPS, Beta 3 moves you to the default provider, because Mullvad is discontinuing that service.

Second beta of Redoubt for Android, built from Firefox ESR 153 with LibreWolf's
patch set. Replaces Beta 1, which should not be used — see below.

What changed since Beta 1

uBlock Origin now ships. It installs itself on first run from a hash-pinned,
Mozilla-signed XPI packaged in the APK (1.74.0), with no fetch from an add-on
collection. It is an ordinary extension: you can disable or remove it.

Firefox branding is gone. Beta 1 shipped Mozilla's trademarks — the Firefox
flame as the home-screen wordmark with the word "Firefox" beside it, five in-app
logos, and eight user-selectable Firefox app icons including the 2004 logo.
Those are replaced throughout. The engine layer is done too: it previously
identified itself as "Fennec" / "Mozilla Fennec" / "Mozilla" inside omni.ja.

Both gaps existed because nothing inspected images or the engine's own branding.
Both now have a gate that runs in CI.

Verify what you downloaded

sha256sum -c SHA256SUMS.signed
apksigner verify --print-certs fenix-<abi>-release.apk | grep -i SHA-256

The certificate digest must be:

64:14:EB:33:46:81:CF:6E:92:90:34:B5:6A:06:2D:2B:8D:A0:90:82:21:72:F7:A3:95:2C:85:FD:D1:28:3B:D0

Signed with APK signature schemes v2 and v3, no v1.

Which file

fenix-arm64-v8a-release.apk for almost any phone from the last several years.
armeabi-v7a for older 32-bit devices, x86_64 for emulators. The universal
APK carries all three and is much larger; prefer a per-ABI build.

Known limitations

• The Gecko content-process sandbox is absent on Android. This is the
  honest headline: Redoubt ships the same privacy configuration and the same
  Gecko-level security patches as LibreWolf desktop, on a platform whose process
  containment is weaker — and we publish exactly where, in docs/android/PARITY.md.
• DNS-over-HTTPS configuration does not apply. Fenix overwrites it on every
  cold start; use the DoH screen in Settings.
• First run makes six Remote Settings requests — certificate revocation, the
  add-on and graphics blocklists, tracking-protection lists. That is a deliberate
  decision, recorded in settings/android.cfg; nothing telemetry-, ads- or
  crash-reporting-shaped is contacted, measured through a resolver that does not
  filter.
• One key holder. Losing that key ends the app under this applicationId.

Provenance

Built from 764fc91c7cbf100705bb456f6a69500ba10f30b9 against Firefox ESR 153.0, three ABIs from one fat AAR,
R8 on. Signed offline by the maintainer; CI never sees the key.