Why settle for a basic build of your Firefox browser on Windows Operating Systems when you can have one that performs 25% faster? Mozilla does not provide optimized browser packages for Windows, while many Linux ("from scratch") users get the advantage of a browser built specifically for their system. That needs to change! So, here is the Pale Moon project: Custom-built and optimized Firefox browsers for Windows Operating Systems. Make sure to get the most speed out of your browser.

Of course, getting a faster browser is not just about optimizing the compilation process (building a program from its source code), but also about carefully choosing features and how to choose the best setup. This means that this browser, however extremely close to Firefox, does not have all the functions that Firefox has. A few, carefully selected, features have been disabled that are not in high demand, and that do not interfere with the way web pages are displayed or function; all to maximize speed and efficiency of the browser. Please see the page with technical details to learn exactly what the browser supports, and what it doesn't support. In short, if you need accessibility features or parental controls, then please visit the firefox homepage and get the official, non-optimized build.


  • Highly optimized for current processors
  • 100% Firefox sourced: As safe as the browser that has seen years of development.
  • Uses slightly less memory because of disabled redundant and optional code
  • Significant speed increases for page drawing and script processing
  • Support for SVG and Canvas
  • Support for Firefox extensions, themes and personas

What's New:


  • Fix plugin doorhanger code for removed-node confusion.
  • Remove Mozilla Corp specific details from search plugins, to clearly indicate the client is Pale Moon and to make sure searches are never counted towards other browser's searches by mistake by search providers.
  • Make sure to set both "warnOnClose" and "warnOnCloseOther" prefs to false when users choose to disable this check in the popup prompt.
  • Update branding: Remove nightly branding altogether - only have unofficial+official, and fix the broken About dialog branding.
  • Bugfix: Clamp level of WebGL TexImage operations to 32-bits to avoid issues on x64 architectures.
  • Update Linux theme: feed icon
  • Bugfix: Add Firefox Compatibility flag to unofficial branding.
  • Workaround for several prominent websites complaining about an "outdated browser".

Security fixes:

  • bug #987003 - Be more careful sandboxing javascript: URLs.
  • bug #952022 - Add missing detachAsmJSModule.
  • bug #986843 - Replace AutoHoldZone with AutoCompartmentRooter.
  • bug #989183 - Check for nsXBLJSClass.
  • bug #980537 - Only store FakeBackstagePass instances in mThisObjects.
  • bug #986678 - Fix type check in TryAddTypeBarrierForWrite.
  • bug #966006 - Fix security issue in DNS resolver.
  • bug #944353 - Avoid spurious decoding of corrupt images.
  • bug #969226 - Avoid buffer overflow in corrupt ICC profiles.
  • bug #991471 - Fix offset when setting host on URL.
  • bug #993546 - Don't try to malloc-free 0-size memory chunks.
  • bug #992968 - Avoid OOM problems with JIT code caching