Pale Moon is a web browser built around the Goanna rendering engine and the UXP application platform. It shares ancestry with older Mozilla code but now follows its own release plan, interface decisions, add-on model, and networking choices. Pale Moon loads ordinary websites, stores bookmarks and passwords, and can synchronise selected browser data through its own service. It does not behave as a current Firefox variant, so a Firefox tweak, extension, or account does not automatically transfer.
Expect rendering differences
Goanna interprets web pages independently from the engines used by current Firefox, Chrome, and Safari. Most ordinary pages use shared standards, but a site written for one tested browser may display a broken control, reject the browser name, or depend on an unsupported media format. Pale Moon can send native, Gecko-compatible, or Firefox-compatible identification to help sites that make crude browser checks.
Changing identification does not add a missing web capability. It only changes what the site thinks the browser is. If a page still fails, use its basic mode or another browser rather than stacking undocumented Firefox preferences onto Pale Moon. The project warns that generic Firefox tuning guides can reduce performance because the underlying defaults differ.
Choose matching add-ons
Pale Moon maintains its own add-ons site and keeps support for the older extension architecture that permits deep interface changes. Some legacy Firefox extensions still work, but compatibility is not guaranteed unless a maintainer tests them against Pale Moon. The browser does not support the WebExtensions model used by most current Firefox and Chromium extensions.
An extension page that names only modern Firefox or Chrome is therefore not a safe compatibility signal. Find a maintained Pale Moon release or a project-specific alternative. Installing several old extensions at once also makes a startup or page failure hard to trace. Add one, restart, and test its main action before adding the next.
Keep profiles separate
A profile contains browsing history, cookies, preferences, passwords, and add-on state. Pale Moon Sync can share supported data between Pale Moon installations, but it does not use the current Firefox Sync account or data format. Importing bookmarks is different from pointing two browsers at one live profile. Do not let Firefox and Pale Moon write to the same profile folder.
A master password protects stored credentials when the browser first needs them during a session. Forgetting that password blocks ordinary access to the saved credentials; it is not the same as a website password reset. Keep a separate recovery plan for important accounts.
Check hardware support
The regular Pale Moon build expects an AVX-capable processor. Older community or legacy builds may exist for processors without AVX, but an outdated build should not become a permanent route for sensitive browsing. Confirm processor support before replacing an existing browser.
Hardware acceleration moves compositing and animation work to the graphics processor. A driver problem can produce flicker, black areas, or crashes. Disabling acceleration is a diagnostic path, though it shifts that work to the CPU. Change the setting only when the symptom points to rendering, then compare the same page after a restart.
