I have been using it for a long time and cannot imagine a browser without this extension.

I can't believe i didn't rate this addon for two years since i ditched noscript because of the new ugly UI.
Well, here i am now, 5/5, it's perfect and easy to use.

This is an extraordinary add-on. I found it to be very intuitive -- there was almost no learning curve. It allows granular control over what web sites may and may not access. It's sad, scary, and wrong how many external sites are referenced by web sites that you visit -- and if any of those sites have been compromised, your computer is likely next. uMatrix provides a simple and effective protection against Internet threats, and as a bonus, helps reduce tracking while speeding up your browsing.

A truly powerful and uniquely capable addon that gives you unrestricted and direct control over your web browsing privacy. The interface and functionality aren't for the faint of heart, and you can easily end up giving yourself a hard time if you don't configure your rules correctly, but for the power user looking to take back control of their personal data on the web this is an invaluable tool with incredible potential. It gives you an inside look at just how many parties are snooping on your browsing habits, and the ability to thwart them directly. Highly recommended.

Eigentlich ist uMatrix ein super AddOn, doch für jede Seite mit einem google ReCaptcha muss dieses extra frei gegeben werden. Auf einigen Seiten öffnet sich jedoch ein PopUp und man hat gar kein Zugriff auf die uMarix-Einstellungen. Das ist einfach mehr als schlecht :(

Works great for me. I see quite a few unwarranted negative reviews, yes it takes some effort by the user to understand what is going on and it's possible to mess things up, but then again you don't look down a racing car just because you don't know how to drive it. It's one of the best and most useful extensions, for both privacy and web testing.