I've tried many alternatives, but Dark Reader is hands down the best. Huge plus for the flexible settings: you can adjust brightness, contrast, add site exceptions, and even tweak fonts. It runs smoothly in Firefox and doesn't hog resources. Huge thanks to the developers!

great fast simple recently after last update it slows my browser

Your last update screwed every single web site I go to, and that is no exaggeration. Every web site now has some random color, changed every color...doesn't even follow my OS or my Firefox settings. This is unacceptable, completely unacceptable. It's going to take me weeks to reset everything. I'm really tired of bad updates.

has been getting extremely laggy recently, even in filter / filter+ mode. Static mode seems fluid but it's a subpar look for websites.

Performance was always icky on Firefox, but recently its just horrible, unusable on low end devices and frequently pushes hardware temps up (the way i even noticed it on main powerful pc, its not felt but you could see high cpu use by stats)

Freezes after last update (Allegro.pl for example).
Zawiesza strony (na przykład Allegro.pl).

It saves my eyes from occational flashbang while surfing the web at night.

Freezes, after last update.

Freezes, cpu util. 20% (ryzen 3900x) - after last update.

The latest update causes the browser and even the entire PC to freeze due to very high CPU usage.

it works now
--- old ---
last update broke something - it slows down the browser and firefox asks if i want to stop this extension

I've been using Dark Reader for years, but now it slows down and even hangs my browser. When I use Firefox Settings to set backgrounds to black, I lose highlighting effects. Absence of a working dark mode could cause me to abandon Firefox. :-(

One of the best extensions I've installed. Simple, effective, and doesn't bloat the browser at all.