Changes all websites to dark mode very reliably. There are occasionally smaller issues if pictures are in the background (text becomes hard to read).
Easily to revert to original. Very low performance penalty, which is worth to have all pages in dark mode.

It's a must to save your eyes! Some sites eventually break, however the extension can be easily deactivated specifically for those.

Works great and very customizable. The only problem is that it likes to theme content inside iframes even if the extension is turned off for both the site inside the iframe and the parent page.

works immediately, does exactly what I want, and has the best configuration settings! :-)

Desde que lo agregé al navegador lo negro se ve de color azúl oscuro, ¿que pasó?

Dark Reader addon has a serious memory leak issue. This problem is affecting users for quite a long time.

SERIOUS MEMORY LEAK. After a month of my laptop locking up and requiring a forced restart I narrowed it down to being Dark Reader with Sepia cranked up to the maximum setting. There's no doubt this is the most effective extension for forcing websites to "go dark". Unfortunately, it's unusable if it freezes your computer every few hours. UPDATE: tried it again a few months later and still the same problem.