uBlock Origin
uBlock Origin is a free, open-source content blocker for browsers. Raymond Hill, known online as gorhill, started the project in June 2014. It blocks ads, trackers, popups, and malware domains before they load. The extension pulls from filter lists like EasyList, EasyPrivacy, and Peter Lowe's list, and you can add your own.
Unlike Adblock Plus, uBO does not take money from advertisers for an 'acceptable ads' whitelist. It also runs lighter on CPU and memory than most blockers in its class. Hill refuses donations for the project itself and tells users to give to filter list maintainers instead. Code is on GitHub. Anyone can read it.
There is a wrinkle on Chrome. Google retired the Manifest V2 extension platform that classic uBO was built on, so Chrome users now install uBlock Origin Lite (uBOL), a stripped-down version that fits Manifest V3 rules. The full extension still works on Firefox, Brave, and Edge. If you want the original feature set, Firefox is the cleanest choice.
- Element picker: point at any chunk of a page and it's gone
- Logger that shows every blocked request live
- Custom filter rules and per-site allowlist switch
- Cosmetic filtering hides leftover page bits that network rules miss
- Block large media or web fonts on a per-site basis
- Hard-block lists for malware and phishing domains
Blocks everything, uses minimal memory, and has never broken a website for me. Essential extension.