Bad performance in Firefox is a known issue and I'm working on improving it. It's not an issue in Chrome and Safari. Low performance can be noticeable in new GMail design, but the reason is their heavy stylesheets full of unused code and images, that Dark Reader tries to analyze. Some day it will be fixed by adding some static themes for popular websites.

a fast and simple alternative for firefox (and android) is this one:

https://addons.mozilla.org/en-US/firefox/addon/night-light-m...

please let us know if it performs better for you! (i'm the author)

I've tried it just a few hours ago, at the moment it's my goto alternative, cheers! The only downside to your extension is that I can't regulate the visual contrast, so some text, like HN content text, is a bit too glaringly bright.

Also, I'm not sure why, but the monospace text in the HN reply box is quite unpleasant to read when inverted.

But good effort! Is it open source?

yup its open source:

https://github.com/conceptualspace/nightlight

and thanks for the feedback!

CSS filters can cause heating of your phone.

Just added the extension to give it a whirl. My CPU usage is 3% to 4%, memory is ~37%, on an i7 wih 16 GB RAM (and about 100 tabs open in Firefox).

I like it. I was looking for something like that for a while. Nighttime browsing on LED monitors seriously hurts my eyes, even with night light settings on. This looks like it'll do the job. I'll know tonight :)

Wish you luck. The resource usage spikes I was experiencing were happening sporadically and some sites were more prone to it than others. I've just installed it again, we'll see how it goes.

I just bought for Safari and immediately uninstalled because CPU usage was too heavy and didn't come down. Also, permissions are way too intrusive, why does the extension need to have access to all of my browsing history?

The browser doesn't separate what injected script can do and what it can't. Regarding Dark Reader, it needs to know page URL to determine if it is blacklisted by your settings or not.

I’m using Night Reader for Safari right now, it allows using hotkeys for toggling between dark and light. Didn’t notice any hit on the performance.

unfortunately still a bit resource intensive, agreed that I like the extension if I ignored that bit

I experienced the same thing. Waiting until the problem is fixed to use again but it was a really useful albeit slow extension.

I have used it a lot on both Firefox and Chrome. It's much slower on Firefox.

With Safari on macOS, the OS reports a negligible energy impact for the extension.

How are you seeing what CPU usage is used on a per extension basis?

I'm not. Wish FF had that.