very effective on both Windows and Ubuntu

This is exactly what I was looking for.

All this does is provide a button in the toolbar to toggle Firefox's own high contrast mode. That mode is minimally configurable from Firefox's settings anyway, but it's a pain to have to open the settings each time you need to turn it on or off. This extension just adds a button to make that convenient.

The Firefox setting for this always affects the whole browser, not per-tab, and it only allows editing of four colours for high contrast mode. That's a limitation of Firefox's setting, not this extension.

Have used for a few days now and is working great compared to the default behavior, which is a constant (literal) headache of digging into the FF settings menu over and over.

The extension makes it super easy to flip back and forth for pages that won't play nice with dark mode.

2 major problems.

1. it disable high contrast for all websites, not just the current tab.

2. When trying to revert back to High-Contrast, it doesn't work properly. You are forced to remove the extension to get High Contrast mode working again.

I couldn't use FF for many years due to the lack of this amazing extension. 🚀🚀🚀

Works well. great when you're sometimes working in bright sun.

Not working for firefox 139. Sets to "customized" instead of automatic, not respecting browser's original configuration. Seems to be out of maintenance so I have to change to 1 star.

Works great, toggle high contrast setting. Allow it to remember settings for a site would be a great addition.

Useless

Somehow, this extension degraded contrast on multiple websites when the high contrast switch was turned OFF.
See https://daverupert.com/about/ for example

This is so much easier than having to change settings on PC. All I needed was to be able to change a page from all black with white font to white with black font. This is perfect and I do not have to reset anything. :)

Switches ALL TABS to high contrast. This makes it not very useful IMO, since it would make more sense to just switch to high contrast in settings.

Simple High Contrast mode switcher. Perfect for e-ink devices like the Pinenote I'm writing this review on. Light on resources compared to CSS modifying addons. Open-source, code available on github.