Mozilla Firefox vs Pale Moon in 2026

Pale Moon is what Firefox would look like if it had refused to change. It forked in 2009, and in 2015 it stopped following Gecko altogether and moved to Goanna, its own hard fork of the engine. That makes this the rare comparison where the two browsers no longer share a rendering engine at all — Firefox is the last major independent engine still in wide use, and Pale Moon is a smaller independent engine descended from it.

The add-on system is the whole argument

Firefox removed XUL and XPCOM extensions in 2017 with version 57, replacing them with WebExtensions. That decision made Firefox faster and safer and broke thousands of add-ons permanently. Pale Moon kept the old system. Its extensions can rewrite core browser behaviour rather than work inside a sandboxed API, which is why some tools that vanished from Firefox nearly a decade ago still run here and nowhere else.

Both browsers score 5 for customizability, but they mean different things by it. Firefox gives you a deep configuration layer and a large modern add-on catalogue. Pale Moon gives you an interface you can dismantle, at the cost of a much smaller catalogue — it scores 3 for extensions against Firefox's 5, because the modern ecosystem simply is not available to it.

What the independent engine costs

Goanna lags well behind on modern web platform features. Complex web apps, some streaming services and anything tested only against Chromium will break or misbehave, and heavy pages are slower because the architecture predates the multiprocess designs everyone else adopted. That is the gap behind Pale Moon's 3 for speed and 3 for ease of use, against 4 and 4 for Firefox.

The practical shape of that is needing a second browser. Most people who run Pale Moon keep something Chromium-based nearby for the sites it cannot handle. Firefox has no such problem.

Reach differs too. Firefox runs on all five major platforms including iOS and Android; Pale Moon is desktop only. Both score 4 for privacy — neither collects the kind of data that would drag the number down, though Pale Moon gets there by having no telemetry at all while Firefox ships some by default and lets you turn it off.

Which should you choose?

Choose Firefox. For almost everyone this is the right answer: the same independent-engine argument, a browser that renders the modern web correctly, sync across your phone and laptop, and a customization layer that goes deeper than most people ever reach.

Choose Pale Moon if you depend on a specific legacy XUL extension that has no modern equivalent, or if you want a browser whose interface you can rebuild from the ground up and you accept that some sites will not work. That is a narrow case, but for the people in it nothing else will do — and the project has kept shipping for well over a decade with no sign of stopping.