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.

DAMN GOOD!

Works in many cases but fails to distinguish between domains and sub domains.

Midnight Lizard works more consistently

Best addon in history