Browser Support • Re: Why is Pale Moon so slow?

Can't speak for Adobe Flash animations (unless of course it enforces some terrible emulation like Ruffle) but in general if there is severe slowness on websites it is because those websites will overload any browser that isn't 100% what it was "designed for" with polyfills for literally everything and the kitchen sink. Even things that are natively supported. i.e. this is often more an exclusionary thing enforced (deliberately or not) by webmasters and/or framework devs rather than a Pale Moon sourced problem.

Our engine is in the same ballpark of performance as Firefox, Chrome and Safari when it comes to raw speed of rendering and javascript. So any big discrepancies seen are due to how websites are being run, code-wise.

As Andy stated this is more visible on ageing hardware, because it will compound there with our single-process design not greedily using every scrap of CPU and RAM a system has.