Updated: October 29, 2026
If YouTube ads suddenly came back, or you see a warning that "ad blockers are not allowed", your blocker did not break by itself: YouTube changes how it serves ads every few weeks, and blockers have to catch up. Here is why it happens and what to try, in order.
Why uBlock stops working on YouTube
- YouTube changed something. New ad formats or anti-adblock checks appear often. Filter lists usually adapt within hours or days.
- uBlock Origin Lite is in basic mode. In Chrome, uBOL can only block YouTube ads properly with a stronger filtering mode, which needs permission to read the site.
- Outdated filters or extension. The fix may already exist, but your copy has not downloaded it yet.
- Two blockers at once. They can interfere with each other and break the video player.
6 fixes, in order
- Reload YouTube with Ctrl+F5 (Cmd+Shift+R on Mac). Sometimes the page cached an old version.
- uBlock Origin Lite: raise the filtering mode on YouTube. Open YouTube, click the uBOL icon and move the slider to "optimal" or "complete". Chrome will ask for permission on that site; accept it.
- Update the extension. Go to
chrome://extensions, turn on Developer mode and click "Update". - uBlock Origin (Firefox): update the filter lists. Open the dashboard, go to "Filter lists" and click "Purge all caches", then "Update now".
- Turn off other blockers and leave only one active.
- Clear YouTube's cookies and cache for the site, then sign in again.
Why does uBlock Origin not work in Chrome at all?
The original uBlock Origin was disabled in Chrome during the move to Manifest V3. If your problem is that it no longer appears or was turned off, read what happened to uBlock Origin in Chrome.
The YouTube "ad blockers are not allowed" warning
YouTube can detect some blockers and show a warning or pause the video. Updating the extension and filter lists usually solves it. YouTube's official alternative is YouTube Premium.
What Qhawa does
Qhawa is built for Manifest V3 and blocks YouTube ads in Chrome without extra modes or settings, skips sponsor segments with SponsorBlock, and updates its rules on its own. If you try it, turn off your other blocker so they do not clash.
Add to Chrome
Frequently asked questions
Why are YouTube ads showing even with uBlock Origin?
Usually because YouTube changed how it serves ads and your filters have not updated yet, or because uBlock Origin Lite is in basic mode on YouTube.
Does uBlock Origin Lite block YouTube ads?
It can, but in Chrome it needs the optimal or complete filtering mode on youtube.com. In basic mode many YouTube ads get through.
Is it safe to use two ad blockers?
It is not dangerous, but it adds little and can break YouTube. Keep one active.
Sources
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