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.

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.

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

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. :)

Fantastic!
Please add a customizable keyboard shortcut option, so anyone can bind this to every button they like

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.