Mull vs Fennec: The Honest 2026 Comparison

Here is the truth most comparison articles skip: Mull was discontinued in late 2024 when DivestOS shut down. Comparing Mull vs Fennec today without saying that is dishonest. The real 2026 comparison is IronFox vs Fennec F-Droid — IronFox continues Mull's legacy. This guide covers all of it, including exactly what to install instead.

Quick Comparison

What Mull Was

Mull was the privacy-hardened Firefox for Android: it stripped Firefox's proprietary components and pre-applied hardening from the Tor Uplift project plus arkenfox-style preferences — anti-tracking, anti-fingerprinting, HTTPS-only mode, per-site permissions. Out of the box, it was the closest thing to "LibreWolf for Android." It was stable enough for daily use and updated promptly with Firefox releases.

Then DivestOS shut down in late 2024, and Mull died with it. Do not install the old Mull builds today — an unmaintained browser is a security risk, no matter how private its defaults were. Old APKs floating around on mirror sites are especially dangerous.

IronFox: Mull's Successor

IronFox is a fork of Mull by a new team, explicitly continuing its legacy. Hands-on testing (MakeUseOf, July 2026) shows it keeps Mull's combative defaults: first-run DNS-over-HTTPS provider choice, optional JavaScript JIT disabling (removes a major attack surface), proxied Safe Browsing, language spoofing, and a uBlock Origin install prompt. It scored 100/100 on an adblock tester against Brave's 96.

The trade-offs are Mull's old ones, honestly kept: some sites break, the password manager and autofill are off by default, heavy web apps run slower without JIT. IronFox is also the browser LibreWolf's own developers recommend for Android — "LibreWolf for Android," in Android Police's words. Install via Accrescent (most secure) or F-Droid.

Fennec F-Droid: The Stable Choice

Fennec F-Droid is Firefox compiled from source with proprietary bits and most telemetry removed — maintained by relan, a respected long-term open-source contributor. It is not hardened like Mull/IronFox: it is essentially vanilla Firefox without the spyware-ish extras, and it still connects to some Mozilla and Google services.

What Fennec gives you: stability, full Firefox Sync, add-ons, and regular updates — a daily driver that looks and behaves like Firefox. If IronFox's breakage annoys you, Fennec plus uBlock Origin gets you 80% of the privacy with 100% of the compatibility. One caveat from the maintainer himself: some about:config changes do not fully apply on Android, so power-user tweaking has limits.

Mull vs Fennec: The Original Technical Difference

For the record, this is how they differed when both were alive:

• Privacy defaults: Mull shipped hardened (Tor Uplift, arkenfox prefs). Fennec shipped Firefox defaults minus telemetry — you hardened it yourself.
• Convenience: Fennec was the smoother daily driver; Mull broke more sites.
• Fingerprinting: Mull's uniform hardened settings made its users look alike; a hand-tweaked Fennec stands out more.
• Updates: both tracked Firefox releases; Mull was sometimes faster.

Today, read "Mull" as "IronFox" in that comparison — the technical relationship is the same.

Which Should You Install in 2026?

• Maximum privacy, some breakage OK: IronFox. The true Mull successor.
• Stable daily driver, de-Googled-ish: Fennec F-Droid + uBlock Origin.
• Just want Firefox without fuss: stock Firefox from the Play Store (4.61 rating, 6.55M reviews) — fine for most people.
• Old Mull APKs: delete them. Unmaintained browsers are unsafe.

How to Install (No Play Store)

1. Install F-Droid (f-droid.org) or Accrescent — both are open-source app stores.
2. For IronFox: add its official F-Droid repo (fdroid.ironfoxoss.org) or get it on Accrescent.
3. For Fennec: search "Fennec F-Droid" in the main F-Droid repo (package org.mozilla.fennec_fdroid).
4. On first run of IronFox: pick a DNS-over-HTTPS provider, decide on JIT, install uBlock Origin when prompted.
5. Sign in to Firefox Sync if you want bookmarks/tabs across devices — sync data is encrypted locally.

Migrating from Mull to IronFox

Still running an old Mull install? Move now — every month without security updates is a risk. The migration is painless:

1. Install IronFox from Accrescent or its official F-Droid repo.
2. In IronFox, sign in to Firefox Sync — bookmarks, history, and tabs transfer encrypted.
3. Reinstall your add-ons (uBlock Origin is offered at setup).
4. Export any local-only data from Mull first (Sync covers most of it).
5. Uninstall Mull. Do not keep it "just in case" — an unpatched browser with your logins is a liability.

What IronFox Kept — and Changed — from Mull

• Kept: Tor Uplift preferences, arkenfox-style hardening, deblobbed build, about:config access, custom add-on collections.
• Changed: first-run setup is more opinionated (DoH provider picker, JIT toggle up front), install recommendation shifted toward Accrescent for stronger signing guarantees, Safe Browsing is proxied rather than stripped.
• Same philosophy: privacy defaults that fight for you, even when it is mildly inconvenient.

Fingerprinting: Why Hardened Defaults Matter

Trackers do not need cookies to identify you. Browser fingerprinting combines dozens of signals — screen size, fonts, language, canvas rendering, WebGL details — into a unique ID. A stock browser with three privacy extensions still has a rare fingerprint: yours. Hardened browsers like IronFox standardize these signals (language spoofing to en-US, uniform settings), so you blend into the crowd. This is the core reason "Fennec + extensions" never fully equals "Mull/IronFox out of the box."

uBlock Origin: The One Add-On That Matters

Whatever Firefox fork you choose, install uBlock Origin:

• Blocks ads, trackers, and malware domains at the network level.
• Open source, no "acceptable ads" program, tiny resource footprint.
• IronFox prompts you to install it during setup; on Fennec, get it from the add-ons manager.
• Optional: enable its stricter blocking modes per-site for banking or shopping.

One honest note: aggressive blocking can break checkout pages and video players. When a site misbehaves, disable uBlock for that site before blaming the browser.

DNS-over-HTTPS: The Setting IronFox Asks About

Normally your internet provider sees every website you look up. DNS-over-HTTPS (DoH) encrypts those lookups. IronFox asks you to pick a provider at first run — options include Mullvad, Cloudflare, and EU-hosted resolvers. Pick one you trust more than your ISP (for most people, that is any of them). This single setting closes a surveillance channel most browser guides never mention.

Gecko vs Chromium: Why This Matters

Almost every Android browser is Chromium-based — Chrome, Brave, Edge, Vivaldi, Kiwi. Firefox forks run Gecko, the only independent engine left. Why care? Engine diversity is a privacy backstop: one Chromium bug or one Google policy change affects nearly everyone, while Gecko users are insulated. IronFox and Fennec keep that alternative alive on mobile. If you value a web that is not defined by one company, using a Gecko browser is a small vote that counts.

The Maintainer Question: Who Do You Trust?

Privacy browsers live or die by their maintainers. A quick trust check:

• Fennec F-Droid: maintained by relan, a long-term open-source contributor (known for exfat-fuse and other infrastructure work). Builds are reproducible from Mozilla's source — you can verify the binary matches the code.
• IronFox: a younger project with a smaller team. The code is open and it inherits Mull's well-understood patch set, but it has less history. Worth watching; already credible enough for daily use according to multiple 2026 reviews.
• Red flags to avoid anywhere: closed-source "privacy" browsers, browsers with no public issue tracker, and any fork that has not updated within a few weeks of a Firefox security release.

Rule of thumb: a privacy browser that is two months behind on security patches is worse than stock Firefox. Check the version number before you commit — and re-check it every few months, because small projects can fade quietly.

FAQs

Is Mull browser still available?

No — Mull was discontinued with DivestOS in late 2024. IronFox is the community successor: a fork of Mull with the same hardened Firefox base, actively maintained in 2026.

What replaced Mull browser?

IronFox, a fork of Mull by a new team. It keeps Mull's privacy-hardened Firefox base (Tor Uplift prefs, arkenfox-style settings) with active updates. Install it via Accrescent or F-Droid.

Is Fennec F-Droid safe?

Yes. Fennec F-Droid is maintained by relan, a long-term open-source contributor. It is Firefox compiled from source with proprietary bits and telemetry removed, available on F-Droid.

Which is more private: Mull or Fennec?

Mull was more private out of the box (Tor Uplift + arkenfox prefs pre-applied). Fennec is vanilla Firefox minus telemetry. Since Mull is discontinued, IronFox is now the hardened option versus Fennec's stable option.

Can I install these browsers from the Play Store?

No. Mull, Fennec F-Droid, and IronFox are not on the Play Store — install via F-Droid or Accrescent. Only stock Firefox (4.61 rating, 6.55M reviews) is on the Play Store.