It should be made clearer before installation that it's not free. Removed.

La primera extensión de pago que me encuentro en firefox... espero no volverlo a ver nunca mas
Recomiendo:
https://addons.mozilla.org/es/firefox/addon/darkreader/

This add on works pretty well for Chrome, but is completely unusable on Firefox. Aside from horrible performance, it also causes issues with Ajax calls and other extensions.

Horrible on Firefox. Makes all websites slow and unresponsive and constantly crashes Firefox. And I have to pay real money for this privilege? Pass.

Completely unacceptable to ask a sub for a simple dark mode. Don't bother with this trash.

Doesn't work on most sites and makes many of the sites it *does* work on completely unusable.

PAYED SUBSCRIPTION !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Payable extension?

Asking for money for a simple dark add-on is simply unacceptable. There are many other choices for free.

I would avoid this addon. While it works very well, as advertised, the developer charges money for it after a 3 month trial. That would have been ok with me, except it's a subscription-based model. Very ridiculous. I would have been ok with paying maybe $5 (which is fair for what it is) for an outright lifetime license. But anyways, I recommend for something similar, try using the addon called 'Dark Night Mode'. It's similar and works well out the box, has a higher rating, and is fully free. For something with more features and customization, I really like 'Dark Reader'.

Messed with pictures and layouts, also with some extensions, for example greasemonkey, couldn't use it at all and setting of night eye were also not functional. No-go for me