YouTube video lag wrongly blamed on its ad-blocking animus

Slowdowns apparently due to a bug afflicting browser extensions, not retaliation against filters

Google claims users of popular ad-blocking extensions have wrongly blamed YouTube for slow video streaming speeds – and that the content filters themselves are the reason for stuttering playback.

The extensions in question are Adblock Plus, a popular browser add-on for zapping adverts before they're shown, and a related one called AdBlock.

YouTube's decision last year to make its policy against ad blocking more visible – by presenting a dialog box during video playback interrupting people to disable such filtering software – may have helped make it the prime suspect in this recent drama.

In November 2023, the Google-owned vid-streaming site confirmed to The Register that it intentionally imposed a page-loading delay for those browsing YouTube while running ad-blocking extensions.

At the time, reports indicated that some individuals not using blocking extensions also experienced loading delays. In response, Google suggested those issues were likely a caching issue for those who had disabled previously active blocking extensions, and that fully reloading a webpage would sort things out.

That suggestion came shortly after privacy advocate Alexander Hanff filed a complaint in Ireland claiming YouTube had violated European privacy law by running ad blocker detection scripts without explicit consent. The complaint remains unresolved.

The Register understands Ireland's Data Protection Commission is likely to delay any decision until the European Data Protection Board rules on a related matter – whether Meta's "Pay or Consent" policy, in which consent for data usage is assumed if a Facebook/Instagram user decides not to pay for a subscription, is lawful.

In light of YouTube's stance on advertising blockers, it's perhaps predictable that people posting to an Adblock Plus support page and to Reddit blamed Google’s streaming service for dismal video performance that seems to have started about a week ago.

Netizens complained their videos were taking longer to buffer, causing spluttering playback, and that this was a result of YouTube deliberately retaliating against ad blockers.

YouTube, however, insists it is not to blame, contrary to some recent coverage of the matter.

"Recent reports of users experiencing loading delays on YouTube are unrelated to our ad blocker detection efforts," a Google spokesperson told The Register in an emailed statement. "Our help center offers troubleshooting tips for users experiencing issues."

Raymond Hill, creator of the open source uBlock Origin ad blocking extension (which isn’t affected by slowdowns), confirmed as much over the weekend in a social media thread by noting that the reported problems can be traced to a bug in Adblock Plus 3.22 and AdBlock 5.17.

While the two tools share a name (but not CamelCase spelling) they are separate but related projects that are both owned by eyeo, an ad-filtering company that gets a fee from large clients for testing, monitoring, and customer-relations services.

The Germany-based biz, run since 2022 by Frank Einecke, former Google managing director of global marketing partners, stated in November 2023 that ad blocking is expected to cost publishers $54 billion in 2024.

According to Hill, the performance issues affecting the two browser add-ons extend beyond YouTube and worsen if users employ multiple ad blocking extensions, which can interfere with one another and magnify computer resource usage.

The bug was removed in the 3.22.1 Adblock Plus release and 5.17.1 AdBlock release.

Hill, unsurprisingly, recommends the free uBlock Origin over alternative blocking extensions based on resource usage, a longstanding issue for extensions that Google has cited as a justification for its Manifest v3 architecture rewrite.

Even in the fixed versions of Adblock Plus and AdBlock (which use the same injected scripts), he said, "[AdBlock's] injected scripts on YouTube still account for over 20 percent of CPU usage," compared to just one percent for uBlock Origin.

Another reason to avoid Adblock Plus and AdBlock, Hill claimed last month, is that both allegedly use a fake progress bar to encourage users of the free extensions to purchase a paid version.

Eyeo did not immediately respond to a request for comment.

Hill observed that the bug appears to be the result of code refactoring undertaken to make the extensions work under Manifest v3. The bug-afflicted Adblock Plus 3.22 release specifically mentions that the update "introduces differential filter list updates, which are crucial to continue delivering frequent updates to filter lists under Manifest v3."

When Google phases out its legacy extension architecture, possibly as soon as June 2024, uBlock Origin is expected to stop working. A less capable version, dubbed, uBlock Origin Lite already functions under Manifest v3. ®

Updated to add

Asked specifically to address Hill’s claim about a fake progress bar, eyeo chief product officer Vegard Johnsen offered a comment that did not address that issue: "Our team is constantly updating our products, and working to anticipate and address any technical issues that may arise – as we did within 48 hours of the recent performance problems on YouTube and other sites following an update – and we use several means to keep users posted."

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