[chicob]

I often use the reader mode in Firefox. Although it is not the same as a dark mode for a whole webpage, it is pretty good at removing clutter and making a web text easier to read. With the added bonus that there are no permissions involved (although I suspect the latter are absolutely necessary for the addon to work, without sharing data to 3rd parties).

It is even possible to save a bookmark in Firefox with reader mode already enabled, by adding about:reader?url= before the url.

[izietto]

There is a nice extension, Automatic Reader View [0], which automatically enables Firefox reader view, if available for the visited page. I even used it in blacklist mode for a while, which wasn't bad but after some time I ended up using it in whitelist mode, because it was too extreme for me.

[0] https://addons.mozilla.org/en-US/firefox/addon/automatic-rea...

[slim]

You can set dark mode in reader view (firefox mobile)

[chicob]

In desktop Firefox there is a dark background option, which is my favorite, along with serif font. I used to postpone my reading list until reading mode came about, because the white screen is just too much sometimes.