You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Raymond Hill 439951824a
Remove addEventListenerLogger, expand addEventListenerDefuser
14 hours ago
.github `actions/create-release@v1`=deprecated, use `ncipollo/release-action@v1` 3 months ago
assets Remove addEventListenerLogger, expand addEventListenerDefuser 14 hours ago
dist Make Firefox dev build auto-update 1 day ago
docs Fix typos in README, docs, and JS comments 1 year ago
platform Import translation work from 5 days ago
src Fix regression in parsing scriptlet arguments 1 day ago
tools Fix crowdin import script 4 months ago
.gitignore git ignore ./tmp/ 7 years ago
.gitmodules Use `git clone` instead of submodule to pull uAssets dependencies 4 months ago
.jshintrc Refactor scriptlets injection code 2 days ago Update 5 years ago
LICENSE.txt first commit 9 years ago Update 8 years ago
Makefile Properly handle default list status changes in assets.json 3 days ago Remove extraneous whitespaces causing misalignement 2 months ago Added data about old popup panel 5 months ago

Badge Commits Badge Issues Badge Localization Badge License Badge NPM Badge Mozilla Badge Chrome

uBlock Origin (uBO)

BEWARE! uBO is (and has always been) COMPLETELY UNRELATED to the website

Get uBlock Origin for Firefox Get uBlock Origin for Chromium Get uBlock Origin for Microsoft Edge Get uBlock Origin for Opera

uBO is NOT an "ad blocker"; it is a wide-spectrum content blocker for Chromium and Firefox with CPU and memory efficiency as primary features. After a new installation, the default behavior of uBO is to block ads, trackers, and malware sites through EasyList, EasyPrivacy, Peter Lowe's Blocklist, Online Malicious URL Blocklist, and uBO's filter lists.


Basic mode Advanced-user mode
Popup user interface A point-and-click firewall that is configurable on a per-site basis


Configure as you wish.
The image shows 3rd-party scripts and frames blocked by default everywhere.

Visit the wiki for documentation.

For support, questions, or help, visit /r/uBlockOrigin.

General Information

uBO is NOT an "ad blocker"; it is a wide-spectrum content blocker. uBO blocks ads through the EasyList filter syntax and extends the syntax to work with custom rules and filters. Furthermore, the advanced mode allows uBO to work in default-deny mode, which will cause all 3rd-party network requests to be blocked by default unless allowed by the user.

It is important to note that using a blocker is NOT theft. Do not fall for this creepy idea. The ultimate logical consequence of blocking = theft is the criminalization of the inalienable right to privacy.

Ads, "unintrusive" or not, are just the visible portion of the privacy-invading means entering your browser when you visit most sites. uBO's primary goal is to help users neutralize these privacy-invading methods in a way that welcomes those users who do not wish to use more technical, involved means (such as uMatrix).

EasyList, EasyPrivacy, Peter Lowe's Blocklist, Online Malicious URL Blocklist, and uBO's filter lists are default enabled when you install uBO. Many other lists are available to block trackers, analytics, and more. Hosts files are also supported.

Once you install uBO, you may easily unselect any preselected filter lists if you think uBO blocks too much. For reference, Adblock Plus installs with only EasyList, ABP filters, and Acceptable Ads enabled by default.


Required Permissions


Chrome Web Store

Microsoft Edge Add-ons (Published by: Nicole Rolls)

Opera Add-ons

Development Build

uBO should be compatible with any Chromium-based browser.

Firefox / Firefox for Android

Firefox Add-ons

Development Build

All Browsers

Do NOT use any other content blocker concurrently with uBO to benefit from its higher efficiency. uBO will perform as well as or better than most of the other popular ad blockers. Other blockers can prevent uBO's privacy or anti-blocker-defusing features from working correctly.

Do NOT use uBO along with other similarly-purposed blockers.

Manual Installation

Enterprise Deployment

Deploying uBO

Release History

Releases Page



Free. Open-source. For users by users. No donations sought.

Without the preset filter lists, this extension is nothing. If you ever want to contribute something, think about the people working hard to maintain the filter lists you are using, which were made available to use by all for free.

You can help contribute by translating uBO on Crowdin.