I use Firefox Quantum 63.0 (32-bit) on Ubuntu.Īn extreme example is loading this stackoverflow page:

When opening the same page in Chrome, it loads fast with the same time for Dark Reader turned on and off - thus it is a Dark Reader problem on Firefox. Also the error message 'a script in Dark Reader is causing Firefox to run slow' is seen regularly when browsing pages. 20 seconds to load in extreme cases when Dark Reader is active. It is rather a pity as it makes using Dark Reader unbearable when a web page takes e.g. I have seen this behaviour on both Ubuntu Linux and on my Android phone. When I turn off Dark Reader, the page will load fast again on the same device. For me, It is not so much the scrolling, but rather that the page simply does not show until after a long time.

I have noticed that web pages are extremely slow in rendering when Dark Reader is activated as compared to when it is turned off in the Firefox browser in the same device. It is definitely not just low PC/mobile performance!

Mozilla firefox browser very slow