uBlock Origin - An efficient blocker for Chromium and Firefox. Fast and lean.
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Build Crowdin License

BEWARE! uBlock Origin is COMPLETELY UNRELATED to the web site ublock.org**

The donations sought by the individual behind ublock.org ("to keeps uBlock development possible", a misrepresentation) are not benefiting any of those who contributed most to create uBlock Origin (developers, translators, and all those who put efforts in opening detailed issues). For the differences between uBlock Origin and uBlock, see the unbiased Wikipedia article.

uBlock Origin is NOT an "ad blocker": it is a wide-spectrum blocker -- which happens to be able to function as a mere "ad blocker". The default behavior of uBlock Origin when newly installed is to block ads, trackers and malware sites -- through EasyList, EasyPrivacy, Peter Lowe’s ad/tracking/malware servers, various lists of malware sites, and uBlock Origin's own filter lists.

uBlock Origin

pronounced you-block origin (/ˈjuːˌblɒk/) — you decide what enters your browser.
English, Chinese (中文), Korean (한국어), Português (Brasil)

An efficient blocker add-on for various browsers. Fast, potent, and lean.


Basic mode Advanced-user mode
Popup user interface A point-and-click firewall which can be configured on a per-site basis


Configure as you wish:
picture shows 3rd-party scripts and frames blocked by default everywhere

Visit the uBlock Origin's wiki for documentation.


uBlock Origin (or uBlock₀) is not an ad blocker; it's a general-purpose blocker. uBlock₀ blocks ads through its support of the Adblock Plus filter syntax. uBlock₀ extends the syntax and is designed to work with custom rules and filters. Furthermore, advanced mode allows uBlock₀ to work in default-deny mode, which mode will cause all 3rd-party network requests to be blocked by default, unless allowed by the user.

That said, it's important to note that using a blocker is NOT theft. Don't fall for this creepy idea. The ultimate logical consequence of blocking = theft is the criminalisation of the inalienable right to privacy.

Ads, "unintrusive" or not, are just the visible portions of privacy-invading apparatus entering your browser when you visit most sites nowadays. uBlock₀'s main goal is to help users neutralize such privacy-invading apparatus — in a way that welcomes those users who don't wish to use more technical, involved means (such as µMatrix).

EasyList, Peter Lowe's Adservers, EasyPrivacy and Malware domains are enabled by default when you install uBlock₀. Many more lists are readily available to block trackers, analytics, and more. Hosts files are also supported.

Once you install uBlock₀, you may easily un-select any of the pre-selected filter lists if you think uBlock₀ blocks too much. For reference, Adblock Plus installs with only EasyList enabled by default.



On average, uBlock Origin does make your browser run leaner. [1]



[1] Details of the benchmark available at Firefox version: benchmarking memory footprint.


uBlock Origin is also easy on the CPU

Details of the benchmark available in this LibreOffice spreadsheet.


Being lean and efficient doesn't mean blocking less

For details of benchmark, see uBlock₀ and others: Blocking ads, trackers, malwares.


Feel free to read about the extension's required permissions.


You can install the latest version manually, from the Chrome Store, or from the Opera store.

It is expected that uBlock Origin is compatible with any Chromium-based browsers.

Important: Chromium-based browsers do not relay websocket connections to the extension API. This means websites can use websocket connections to bypass uBO (or any other blocker). This can be remediated by installing uBO's companion extension uBO-Extra.

Firefox / Firefox for Android

Firefox Add-ons web site. There is also a development version if you want to test uBlock Origin with the latest changes: see uBlock Origin Version History

uBlock Origin is compatible with SeaMonkey, Pale Moon, and possibly other browsers based on Firefox.

The Firefox version of uBlock Origin has an extra feature currently not yet available on Chromium-based browsers -- which feature is of great help to foil attempts by many web sites to circumvent blockers.

Also of interest: Deploying uBlock Origin for Firefox with CCK2 and Group Policy.

Thanks to Debian contributor Sean Whitton, users of Debian 9 or later or Ubuntu 16.04 or later may simply apt-get install xul-ext-ublock-origin.

Microsoft Edge

Developer: @nikrolls.

Stable version available in Microsoft Store.

Development version available at https://github.com/nikrolls/uBlock-Edge#edge.

Safari (macOS)

Developer: @el1t.

Development version available at https://github.com/el1t/uBlock-Safari#ublock-originfor-safari.

Note for all browsers

To benefit from uBlock Origin's higher efficiency, it's advised that you don't use other inefficient blockers at the same time (such as AdBlock or Adblock Plus). uBlock₀ will do as well or better than most popular ad blockers.

Release History

See the releases pages for a history of releases and highlights for each release.


uBlock Origin's manifesto.

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

Without the preset lists of filters, this extension is nothing. So if ever you really do 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 contribute by helping translate uBlock₀ on Crowdin.