uBlock Origin
The content blocker every other blocker is measured against: fast, free, open source, and still the gold standard on Firefox.
About
uBlock Origin is Raymond Hill's free, open-source content blocker for Chromium and Firefox, maintained on GitHub under the GPLv3 with about 68,000 stars. It blocks ads, trackers, cryptominers, and malware domains through both network filtering and cosmetic filtering, and it adds an element picker, dynamic per-site rules, scriptlet injection, and a request logger for people who want fine-grained control. It is deliberately lean: the engine does its work with minimal CPU and memory overhead compared to the heavyweight ad blockers, and it accepts no payment from advertisers, which is the point where several competitors compromised.
The defining story of the last two years is Google's Manifest V3 transition. uBlock Origin is a Manifest V2 extension relying on the blocking webRequest API, and Google removed MV2 extensions from the Chrome Web Store in August 2026, so the full version is no longer installable there. Hill's answer is uBlock Origin Lite, a pared-down MV3 version, but it sacrifices features that cannot work within MV3's declarativeNetRequest framework. Development of the full version continues where MV2 still lives, primarily Firefox, which Hill's own documentation says is where uBO works best. The extension is free with no account and no data collection. Independent performance figures come from the community rather than the project, so treat speed claims as third-party measured.
What it can do
- Network and cosmetic filtering for ads, trackers, and miners
- Element picker and per-site dynamic rules
- Scriptlet injection and advanced request logger
- Dozens of maintained filter lists, community updated
- Minimal CPU and memory footprint by design
- No acceptable-ads program and no data collection
- UBlock Origin Lite for Manifest V3 browsers
- Enterprise deployment and Thunderbird support
Setup
Install from Firefox Add-ons, Edge Add-ons, Opera Add-ons, or the GitHub releases; on Chrome, use uBlock Origin Lite or switch to Firefox for the full version.
Prerequisites
A compatible browser; nothing to sign up for.
Use cases
Works with
Trust score — 9/10
Scored 9/10 (verified tier, metrics-v1). Evidence: the GitHub repo (gorhill/uBlock, GPL-3.0) shows ~67,953 stars with active development; the project's own wiki documents the MV2/MV3 situation, the Chrome Web Store removal in August 2026, and the Firefox-first status. Strengths: the most effective and efficient blocker available, maintained for a decade with zero commercial compromise. Docked for: (1) the full version is unavailable in the Chrome Web Store post-MV2, with Lite losing features; (2) a single primary maintainer, however respected; (3) advanced power can break sites for beginners. License: GPL-3.0.
★ 67,953 GitHub stars
How the trust score is built
Full methodology →- Adoption · stars/downloads, log-scaled vs peers
- 10.0/10
- Maintenance · recency, releases, issue load
- 9.0/10
- Openness · license + docs
- 10.0/10
- Manual review · sanity read + red-flag check
- 9.0/10
- · Raymond Hill (gorhill); gorhill/uBlock on GitHub; ~67,953 stars; active since 2014
- · Network + cosmetic filtering, element picker, dynamic rules, scriptlet injection
- · Minimal CPU/memory footprint by design; accepts no advertiser payments
- · Manifest V2 extension: removed from Chrome Web Store August 2026
- · uBlock Origin Lite is the pared-down MV3 version with fewer features
- · Full version development continues; Firefox is the first-class platform
- · Single primary maintainer
Sources
Every fact above was checked against these sources. Where a claim comes from the provider and couldn't be independently verified, the text says so.