uBlock Origin

uBlock Origin (uBO) is a wide-spectrum content blocker for Chromium-based browsers and Firefox, written in JavaScript and released under the GPL-3.0 license. It is designed to be efficient with CPU and memory, and the project names Firefox as its preferred browser.

By default it blocks ads, trackers, coin miners, popups, anti-blocker scripts and malware sites using filter lists such as EasyList, EasyPrivacy, Peter Lowe's Blocklist and the Online Malicious URL Blocklist, and it can load many other lists. It is installed from the add-on stores of Firefox, Edge and other browsers, or from stable and development builds published on GitHub.

Availability is changing on Chromium browsers because Chrome and Edge are phasing out Manifest V2 extensions, and the README points to uBlock Origin Lite as a related project. Manually installed Chromium and Thunderbird builds usually do not update themselves. It suits anyone who wants a privacy-focused ad blocker with fine control over filters.