Firefox Forks Explained: Waterfox, Pale Moon and LibreWolf Compared

Waterfox, Pale Moon and LibreWolf are independent web browsers built from Mozilla Firefox source code, each changing Firefox in a different direction. LibreWolf is the closest to current Firefox but with strict privacy settings switched on, Waterfox is a lightly modified Firefox with fewer Mozilla services and more user control, and Pale Moon is a much older branch of Firefox code that keeps the classic interface and legacy add-ons at the cost of compatibility with many modern websites. For most people, standard Firefox or LibreWolf is the safer everyday choice.

What is a Firefox fork?

A Firefox fork is a browser made by taking Firefox’s open-source code and releasing a modified version under a different name. Firefox is published under the Mozilla Public License, which allows anyone to do this as long as they follow the license terms and do not use Mozilla’s trademarks.

Forks usually exist for one of three reasons:

Privacy: removing telemetry, sponsored content and built-in services that contact Mozilla or partners.
Control: keeping or restoring settings and features that Mozilla removed or hid.
Legacy support: preserving the older interface and the old add-on system that Firefox dropped in 2017 when it moved to WebExtensions.

The trade-off is that a fork depends on a smaller team. Security fixes come from Mozilla first, and every fork has to merge them and ship its own update, which can take extra days or longer.

How is LibreWolf different from Firefox?

LibreWolf is current Firefox with privacy and security settings tightened by default and Mozilla’s data collection removed. It follows Firefox’s regular release versions closely, so websites behave almost exactly as they do in Firefox.

Key differences out of the box:

No telemetry, crash reporting or studies sent to Mozilla, and no sponsored shortcuts or suggestions.
The uBlock Origin content blocker comes preinstalled.
Fingerprinting resistance is turned on, which can make sites show the wrong time zone or a generic window size.
Cookies and browsing history are cleared when you close the browser, so you are signed out of sites each time unless you add exceptions.
DRM video playback (Widevine), used by some streaming services, is off by default and has to be enabled in settings.
Firefox Sync is disabled by default but can be switched back on.

The main practical catch is updates. On Windows, LibreWolf does not quietly update itself the way Firefox does; you update through a package manager, an optional updater tool or by downloading new versions yourself. Falling behind on updates undoes much of the privacy benefit, because an outdated browser is easier to attack.

How is Waterfox different from Firefox?

Waterfox is a Firefox-based browser that removes telemetry and Mozilla’s sponsored features while keeping defaults close to normal Firefox, so it feels familiar without LibreWolf’s stricter settings. It began years ago as one of the first 64-bit builds of Firefox for Windows and later shifted its focus to privacy and user choice.

What to expect:

It is built on Firefox’s Extended Support Release (ESR) code, which gets security fixes but receives new features less often than regular Firefox.
It uses the normal Firefox add-on store, so most Firefox extensions work.
It includes extra interface and tab options that Firefox does not offer.
Sites generally work as they do in Firefox, and you can stay signed in, unlike LibreWolf’s default.

An older Waterfox Classic edition, which supported legacy add-ons, is outdated and should not be used for everyday browsing. If you choose Waterfox, use the current main version from the official website.

How is Pale Moon different from Firefox?

Pale Moon is the most different of the three: it split from Firefox code many years ago and develops its own engine, called Goanna, on a platform known as UXP. It does not follow modern Firefox releases at all.

It keeps the classic Firefox look, with a traditional menu bar and fully customizable toolbars.
It supports old-style XUL add-ons through its own add-on site, but not most modern Firefox extensions.
It runs well on older or low-powered computers.
Official builds are for Windows and Linux; there is no official macOS version.
Firefox Sync does not work with it.

The big downside is compatibility. Because the engine is separate from Firefox, some modern websites and web apps load slowly, display incorrectly or refuse to work. Pale Moon suits enthusiasts who value the classic interface and accept that some sites will need a second browser.

Which Firefox fork should you choose?

The right choice depends on what bothers you about Firefox:

You want maximum privacy with modern compatibility: LibreWolf, as long as you keep it updated and are comfortable adding cookie exceptions for sites you use daily.
You want Firefox without telemetry and with defaults you do not have to fight: Waterfox.
You want the classic interface and old add-ons, or you run an older PC: Pale Moon, ideally alongside a modern browser for banking and web apps.
You want the fastest security updates and the least hassle: stay with Firefox and adjust its privacy settings yourself.

Firefox itself can be made quite private: open Settings, then Privacy & Security, choose Strict Enhanced Tracking Protection, turn off the data collection options at the bottom of that page, and install uBlock Origin from the Firefox add-on store.

Are Firefox forks safe to use?

Well-known forks downloaded from their official websites are generally considered safe, but they are only as secure as their last update. Keep these points in mind:

Download only from the project’s own website or a trusted package manager, never from a third-party download portal.
Check for updates regularly, especially after Mozilla announces a security release.
Do not install an abandoned or discontinued edition of any browser.
Be aware that small teams can change direction, change ownership or stop development; keep your bookmarks and passwords exported or backed up.

Can you move bookmarks and passwords from Firefox to a fork?

Yes, bookmarks and passwords can usually be moved from Firefox to LibreWolf or Waterfox. Both offer an import option in their bookmarks manager, and you can also export Firefox bookmarks to an HTML file and passwords to a CSV file, then import them. LibreWolf and Waterfox can also use Firefox Sync once it is enabled. Pale Moon has a separate profile format, so importing an HTML bookmarks file is the most reliable route.

Quick answers

Are there other Firefox forks?

Yes. Other Firefox-based browsers include Floorp, Zen Browser and the Tor Browser, which is built on Firefox ESR and routes traffic through the Tor network. Each has its own focus, from interface design to anonymity.

Do Firefox forks use less memory than Firefox?

LibreWolf and Waterfox use roughly the same resources as Firefox because they share its engine. Pale Moon can be lighter, which is why it is popular on older machines; if your computer struggles with every modern browser, it may be time to read about choosing a laptop with the right CPU and RAM.

Can you run a fork alongside Firefox?

Yes. Each fork installs as a separate program with its own profile, so you can keep Firefox for some tasks and use a fork for others without them interfering.

Do Firefox forks work on phones?

Mostly not. LibreWolf, Waterfox and Pale Moon focus on desktop computers. On Android, Firefox itself supports add-ons such as uBlock Origin, which covers much of the same ground.