It looked better than some dark theme addons but it slowed my Firefox program down way too much on any website. I have a beast computer. i7 5820k, 2080ti, 32gb ram.

Works amazingly well right out of the box. Could not recommend enough.

Truly remarkable, the UX is absolutely incredible

This is how addons should be - I can adjust everything, because here I AM the boss!

nice addon!!

Finally! Great dark mode extension with a blue light filter and LOOOADS of ways to customize things. The best thing? It preserves the web page's elements and styles flawlessly. Great app, thank you!

Wonderful extension! Working perfect on almost all the websites.

Just a curious notable exception : on Amazon it slows down drastically the progressive display of the pages while I don't encounter this issue using darkreader (other excellent extension but less flexible). So I use both, depending on whether I'm on Amazon or elsewhere.

Could you see what could be the cause in Midnight Lizard's code?

Midnight Lizard will largely be the best with that optimization of the execution speed on such very popular websites with lots of elements.

Thanks!

[EDIT 2019-05-30]
Great!
Thank you Pavel !
The page you've linked (just below) is very smart with its descriptive screenshots coming with the text. I'm going to make experiments with the advices it contains.

About the other similar extensions (darkreader in my case) no, there is no risk... for the moment I use them both as if it were with a switch button: always only one enabled in the FF add-ons page (as a kind of logical XOR gate in mind).

Thanks a lot for your answer!

Wonderful app! It give to ma' brain a little relax. B)

Exelent, better developed than other extensions.

Years of uni in front of a computer have really messed with the eyes, even tried blue-block glasses, but oddly took them of at night! Almost every websites blinding white background is a pain (for me) . This add-on is is awesome, some sites need a little tweaking, lesser ones used I guess, e.g., some some bars and captions don't like the change, but a little tweak here and there and you will have a much better experience, if that's your thing. I use Firefox and it can be a little intensive, but an occasional complaining yellow bar is hardly an inconvenience when you conciser what's going on behind the scenes.
I'm not normally a review writer, but this is deserving, top marks for Pavel Agarkov for Midnight Lizard. Well worth a small donation.