Really useful for blocking unwanted web fetches while I am inside any Internet Banking Secure sites Eg., block www.google-analytics.com and the same applies to the sharemarket logons, I dont NEED or WANT a facebook icon while I am doing business!!
Another use is browsing from behind the Great China Firewall. Many sites have facebook and google icon/links type "fetches", these cause pages never to complete, Eg., browsing Western news sites, or even StackExchange and GitHub.
As measured by WebMIn (visually) ...about 2.25Gig RAM Released by FireFox on an 8Gig Linux workstation.

Excellent, should come by default in every browser.

好用

Excelente miren no hay ningún bloqueador como el de ustedes este es el mejor y es mi favorito además de ser de código abierto excelente me encanta si los navegadores de Android tuvieran está extensión sería un gran logro para ellos por el momento sólo Firefox me da esa opción y es un excelente navegador por no ser igual a los demás sigan así!!!

Bien

Cool

A melhor que tem. Bloqueia anúncios, páginas maliciosas, anúncios de malvertising, mineradores de bitcoins e mais.

I use uBlock Origin in addition to uMatrix. uBO primarily replaced 5 addons I used in the past. But even if it would've only replace one addon out of those 5 I'd have switched. Never regretted it.

Best Blocker so far! Really good work!

It doesn't slow my browser.

Ad-blocking done right.

非常有效 使用上沒有任何干擾

This extension blocks ads superbly. I used another extension for years, but the lower resource utilization and straightforwardness got me to move to uBlock Origin. Many webpages can somehow detect that ads are being blocked; I wish there was a workaround for this. But this does an excellent job blocking the ad-scourge of the Internet.

Всё супер!

Getting more and more ads these days