Summary
uBlock Origin is a free and open-source, cross-platform browser extension for content filtering, including ad-blocking. uBlock Origin's stated purpose is to give users the means to enforce their own (content-filtering) choices.
Body
Overview
uBlock Origin is a free and open source, cross-platform browser extension for content-filtering, including ad-blocking. uBlock Origin has received praise from technology websites, and is reported to be much less memory-intensive than other extensions with similar functionality. uBlock Origin's stated purpose is to give users the means to enforce their own (content-filtering) choices.
NOTE: There is another similarly named browser extension called simply "uBlock" (not "uBlock Origin"). We recommend users not install the other "uBlock" extension.
Installation
Click one of the links below for your preferred browser:
Once installed, you will see a red shield icon in your browser window:
The number next to the shield shows how many ads and other outside content have been blocked. See the documentation section for more information.
Disabling uBlock Origin for sites
If you experience problems rendering a web site, you can easily temporarily disable uBlock Origin by clicking the shield icon, then clicking the power button icon:
Official uBlock Origin Documentation