uBlock Origin (uBO)
What is this?
uBlock Origin (uBO) is a free, open-source browser extension that blocks ads, trackers, coin miners, popups, anti-blockers, and malware sites in Chromium and Firefox.
uBlock Origin (uBO) is a free, open-source browser extension that blocks ads, trackers, coin miners, popups, anti-blockers, and malware sites in Chromium and Firefox.Is this one extension or different builds per browser?It is the same extension distributed separately for each browser store (Firefox, Edge, Opera) plus manual builds for other Chromium browsers and Thunderbird.
It is the same extension distributed separately for each browser store (Firefox, Edge, Opera) plus manual builds for other Chromium browsers and Thunderbird.Is it still on the Chrome Web Store?No. All remaining Manifest V2 extensions, including uBO, were removed from the Chrome Web Store on August 31, 2026, so Chromium users now need manual installation and won't get auto-updates.
No. All remaining Manifest V2 extensions, including uBO, were removed from the Chrome Web Store on August 31, 2026, so Chromium users now need manual installation and won't get auto-updates.Which browsers does it actually support?It works on Firefox desktop and Android (its best-supported platform), any Chromium-based browser, Microsoft Edge, Opera, and Thunderbird (where it only filters feeds, not emails).
It works on Firefox desktop and Android (its best-supported platform), any Chromium-based browser, Microsoft Edge, Opera, and Thunderbird (where it only filters feeds, not emails).What does it block by default and can I change that?By default it uses EasyList, EasyPrivacy, Peter Lowe's Blocklist, the Online Malicious URL Blocklist, and uBO's own filter lists, plus hosts-file support; any of these lists can be unchecked if you think it blocks too much.
By default it uses EasyList, EasyPrivacy, Peter Lowe's Blocklist, the Online Malicious URL Blocklist, and uBO's own filter lists, plus hosts-file support; any of these lists can be unchecked if you think it blocks too much.Is it really free, no catch?Yes, it is fully free and open source under GPLv3, with the project explicitly stating it seeks no donations.
Yes, it is fully free and open source under GPLv3, with the project explicitly stating it seeks no donations.What is the difference between Basic and Advanced Mode?Basic Mode is an install-and-forget setup configured optimally by default, while Advanced Mode adds a point-and-click firewall you can configure per site.
Basic Mode is an install-and-forget setup configured optimally by default, while Advanced Mode adds a point-and-click firewall you can configure per site.Can I run uBO alongside another ad blocker?No, the project advises against it: other blockers can interfere with uBO's privacy and anti-blocker-defusing features, even though uBO alone performs as well as or better than most popular blockers.
No, the project advises against it: other blockers can interfere with uBO's privacy and anti-blocker-defusing features, even though uBO alone performs as well as or better than most popular blockers.Does uBO affect my Thunderbird emails?No, in Thunderbird uBlock Origin only filters RSS/Atom feeds and does not touch emails.
No, in Thunderbird uBlock Origin only filters RSS/Atom feeds and does not touch emails.Does the author consider ad blocking to be theft?No, the README explicitly rejects that framing, arguing blocking is a defense of the inalienable right to privacy against privacy-invading tracking methods, not theft.
No, the README explicitly rejects that framing, arguing blocking is a defense of the inalienable right to privacy against privacy-invading tracking methods, not theft.What are similar projects?cat-catch, SponsorBlock, desktop_gifs, anti-AD, SwitchyOmega, return-youtube-dislike, bare-browser, kiss-translator
cat-catch, SponsorBlock, desktop_gifs, anti-AD, SwitchyOmega, return-youtube-dislike, bare-browser, kiss-translatorWhich topics is it in?filtering, ad-blocker, adblock, chromium, firefox, extension, firefox-extension, chrome-extension, browser-extension, desktop, gplv3, android
filtering, ad-blocker, adblock, chromium, firefox, extension, firefox-extension, chrome-extension, browser-extension, desktop, gplv3, android