Official project (gorhill/uBlock)
uBlock Origin - Free, open-source ad blocker extension
Professional-grade content blocking, easy on CPU and memory.
uBlock Origin is not just an ad blocker. It is a wide-spectrum content blocker and browser extension designed for efficient ad, tracker, and malicious-domain filtering with low CPU and memory usage.
What does uBlock Origin block?
uBlock Origin is a free ad blocker that uses community-maintained filter lists to block unwanted requests and hide clutter on web pages. This open-source adblocker covers more than advertising:
Ads
Filters banner ads, advertising scripts, and many video ads in your browser. Blocking depends on the website and current filters; no ad blocker can guarantee every ad will disappear.
Trackers
Blocks requests to known tracking servers and scripts covered by your filter lists. It reduces online tracking, but does not make you anonymous or stop every way a website can collect data.
Pop-ups
Stops unwanted pop-up windows and tabs when they match blocking filters. Full uBO also has a per-site pop-up switch for sites that need stricter blocking.
Unwanted page elements
Hides ad placeholders and other matching page elements. Use the element picker to create your own hiding filters, or enable optional annoyance lists for items such as cookie banners and overlays.
Browser-only coverage: the extension works in the browser where you install and enable it. It does not block ads in other apps, games, or on other devices. Results depend on your browser, filter lists, permissions, and the site; filtering can occasionally break a page, so you can turn it off for that site.
uBlock Origin Lite vs. uBlock Origin
uBlock Origin Lite (uBOL) is Raymond Hill's content blocker built for Manifest V3, the extension platform used by current Chrome. It uses browser-managed filtering rules. Full uBlock Origin (uBO) offers more filtering capabilities and advanced controls, with the strongest support on Firefox.
| Feature | uBlock Origin | uBlock Origin Lite |
|---|---|---|
| Supported browsers | Firefox on desktop and Android. Chromium browsers must still support Manifest V2; Edge is phasing it out. Full uBO is unavailable in current Chrome or Safari. | Chrome, Edge, Firefox, and Safari. The official project links to each browser’s store; features can vary by browser. |
| Filtering modes | Full filtering and advanced controls. Network and cosmetic filtering by default, with optional dynamic filtering and per-site controls. | Four simple filtering modes. No filtering, Basic, Optimal, and Complete, set per site or as a default. Does not include full uBO’s dynamic filtering controls. |
| Custom filters | Create and fine-tune your own filters. Use the element picker, edit My filters, or subscribe to external filter lists. | Custom filters and imported lists. Current versions also include an element picker. Browser API limits apply; not every uBO filter can be used. |
| Permissions | Broad website access. Uses website data and web requests to inspect, block, and modify content. | Access depends on the mode. Basic can work without website read/modify access. Optimal and Complete need it; custom cosmetic and scriptlet filters may also require enabling user scripts. |
| Who is it for? | For full control, especially on Firefox. From default blocking to detailed rules and troubleshooting tools. | For straightforward blocking. Especially on Chrome or another browser that requires Manifest V3. |
Which Lite filtering mode should you use?
- No filtering: turns filtering off for a trusted site or while troubleshooting.
- Basic: blocks network requests using selected lists, without needing to read or change page content.
- Optimal: adds more network filtering and site-specific page cleanup, including cosmetic and scriptlet filters.
- Complete: adds generic cosmetic filtering to hide matching elements across sites. This can use more page resources.
Choose Optimal or Complete if you want page cleanup as well as network blocking, and grant the required website access. Lite can be less effective on sites using anti-ad-blocking techniques because some full uBO filters cannot be translated to Manifest V3 rules.
Firefox installation guide (English)
Official Lite browser downloads
Lite FAQ (English)
Permissions guide (English)
Frequently Asked Questions
Does uBlock Origin block YouTube ads, and what if it stops working?
It can block YouTube ads in your browser, but results change as YouTube changes its systems. If ads return:
- Update your browser and extension, and check that blocking is enabled for youtube.com.
- In full uBO, update your filter lists and keep the default lists enabled. In Lite, select Optimal mode for YouTube and allow the required website access.
- Temporarily disable other ad blockers and custom YouTube filters to check for conflicts. Close your YouTube tabs and test in a new tab.
- If the problem persists, follow the official uAssets YouTube troubleshooting thread for your extension. Include its Troubleshooting information when reporting.
Neither extension filters the YouTube app or guarantees uninterrupted blocking.
Does uBlock Origin work on Twitch?
Twitch video ads are not reliably blocked by uBlock Origin or Lite. Ads integrated into a stream can be difficult to separate from the video. The extension may still block other matching ads and trackers on the Twitch website, but does not filter the Twitch app.
Is uBlock Origin free?
Yes. uBlock Origin is completely free and open-source. The project does not accept donations and instead encourages users to support filter list maintainers.
What browsers support uBlock Origin?
Full uBlock Origin works best on Firefox, including Firefox for Android. Chromium browsers need continued Manifest V2 support; Edge is phasing this out. Current Chrome and Safari cannot run full uBO. uBlock Origin Lite is available for Chrome, Edge, Firefox, and Safari.
Why is uBlock Origin no longer supported on Chrome?
Chrome removed Manifest V2 support, which full uBlock Origin requires. uBlock Origin Lite supports Manifest V3 and is available separately for Chrome. Use Firefox if you want the full extension and its advanced filtering controls.
Is uBlock Origin safe to use?
The official uBlock Origin is open-source, and its privacy policy says it does not collect user data. Install it through the browser-store links in Raymond Hill's official GitHub project, keep it updated, and avoid similarly named copies. It can reduce exposure to unwanted content, but it is not antivirus software and cannot make every website safe.
Why does uBlock Origin need permission to read and change website data?
Full uBO needs access to web requests and page content to block ads and trackers, hide unwanted elements, and apply filters. Its tab permissions support per-site controls and pop-up blocking. These permissions describe what it can access, not a claim that it collects your browsing history. Lite's Basic mode can work without website read/modify access; Optimal and Complete need that access for fuller filtering. Restricting site access can reduce what the extension blocks.
How do I disable uBlock Origin for one website?
You can turn off blocking for one website while continuing to filter other sites.
- Open the website and click the uBlock Origin icon in your browser.
- In full uBO, click the large power button. In Lite, move the filtering slider to No filtering.
- Reload the page. The extension will remember your choice for that site.
To re-enable blocking, click the power button again in full uBO, or restore the previous mode in Lite, then reload.
Can I use uBlock Origin on Android?
Yes. Install Firefox for Android, then add uBlock Origin by Raymond Hill from Mozilla's official Firefox Add-ons listing. It filters websites you open in Firefox. Chrome for Android does not support desktop Chrome extensions, so installing Lite on your computer does not add it to your phone. Neither extension provides device-wide blocking or removes ads inside Android apps such as YouTube.
Can I use uBlock Origin on iPhone or iPad?
Full uBlock Origin is not available for iPhone or iPad. uBlock Origin Lite is available for Safari:
- Install uBlock Origin Lite by Raymond Hill from the App Store.
- Open Settings > Apps > Safari > Extensions, select Lite, and turn on Allow Extension.
- Grant the website access needed for your filtering mode.
This filters websites in Safari. It does not remove ads from the YouTube app, other apps, or other browsers on your device.
About uBlock Origin
uBlock Origin is a free, open-source content blocker created and maintained by Raymond Hill. First released as uBlock in 2014, it uses community-maintained filter lists to block unwanted content on the web.
The project does not accept donations. It encourages users who want to contribute financially to support the people who maintain filter lists.
Official project on GitHub. This website is an independent, unofficial guide.