Excellent! Just what I was looking for.

It's amazing. I'd never have thought that it's possible to 'darkify' web pages in this quality. Almost like a horde of little, dark loving, aesthetically talented people living inside my browser.

That's great useful extension. Special thanks to the developers of that.

Thank you!
This add-on was very useful. it change the background to dark on every site correctly. 👍

thanks.. can you make it work for pdf files viewed in firefox too? also it seems it is not working on the addons website itself (at least not right now for me)

Perfect, just what I needed and utterly indispensable. Many thanks.