Back in June, Google's Chrome Web Store began alerting users of uBlock Origin who had developer-oriented versions of Chrome that the popular ad-filtering extension could soon stop working.

With the stable release of Chrome 127 on July 23, 2024, the full spectrum of Chrome users could see the warning. One user of the content-blocking add-on filed a GitHub Issue about the notification.

"This extension may soon no longer be supported because it doesn't follow best practices for Chrome extensions," the Chrome Web Store (CWS) notification banner explained.

But Google is being too cautious in its language. uBlock Origin (uBO) will stop working entirely when Google Chrome drops support for Manifest v2 - which uBlock Origin and other extensions rely on to do their thing. When Manifest v2 is no longer supported by Chrome, uBlock Origin won't work at all - that's what Google should be telling users.

You will have to find an alternative to uBO before Google Chrome disables it for good

Raymond Hill, the creator and maintainer of uBO, has made it clear that he will not be trying to adapt uBO to Google's Manifest v3 - the extension architecture that is replacing v2.

"You will have to find an alternative to uBO before Google Chrome disables it for good," he explained in a list of FAQs for uBlock Origin Lite - a content-blocking extension that functions on the upcoming Manifest v3 system but lacks the ability to create custom filters.

uBlock Origin Lite, he explained, is "not meant as a [Manifest v3]-compliant version of uBO, it's meant as a reliable Lite version of uBO, suitable for those who used uBO in an install-and-forget manner."

This is a nuanced statement. He's not saying that if you move from uBO to uBlock Origin Lite all will be well and exactly the same - just that uBlock Origin Lite works on Manifest v3, so it will continue working after the v2 purge.

This nuance is needed because Manifest v2 provided uBlock Origin and other extensions deep access to sites and pages being visited by the user. It allowed adverts and other stuff to be filtered out as desired, whereas v3 pares back that functionality.

While it's difficult to generalize about how the experience of uBO under Manifest v2 and uBOL under Manifest v3 will differ, Hill expects uBOL "will be less effective at dealing with" websites that detect and block content blockers, and at "minimizing website breakage" when stuff is filtered out, because existing uBO filters can't be converted to declarative rules.

Manifest destiny

In 2018 Google announced plans to rewrite the Chrome Extension platform - the set of APIs available to developers of Chrome extension. The legacy scheme, Manifest v2, would be phased out and replaced by Manifest v3.

Manifest v3 curtailed much of the power of the prior extension regime, which could be (and was) easily abused. It did so in the name of security, privacy, and performance - by disallowing, for example, the execution of remotely hosted scripts and requiring that content filtering rules are declared in advance rather than dynamically. (That limitation has eased somewhat.)

One of the consequences of the transition, now supported to varying degrees by other browser makers, is that content blocking and privacy extensions are expected to become less capable due to the limitations of the Manifest v3 APIs.

While Manifest v3's capabilities have been improved in response to feedback - and outfits including AdGuard have expressed cautious optimism - platform improvements haven't made it possible to port uBlock Origin to the new API in a way that retains the desired functionality.

Google has been dropping Manifest v2 support from Chrome gradually since June 2024 in its developer-oriented browser release channels (Canary, Dev, and Beta). But it's still not clear when support will end completely.

Google didn't immediately respond to a request to clarify when Manifest v2 support will be dropped from the Chrome Stable release channel, but the appearance of a warning banner in the CWS suggests the end is near.

(Enterprise users with managed versions of Chrome have a bit longer, which has led some to contemplate a registry edit to set Chrome's enterprise flag.)

An estimated 34 million people have installed uBO to filter content in Chrome, according to CWS statistics. And a handful of these have already begun making their displeasure known in CWS reviews of the extension.

"As an IT administrator, uBlock Origin is a requirement for our users," wrote one individual posting under the name Kendoka on Monday. "As a personal user, I hereby swear to uninstall Chrome the day ad blockers are removed."

The other ten reviews posted on August 5, 2024 make similar statements. "If or when Chrome kills this extension, I will move to Firefox and never return," wrote someone posting under the name Henry A.

At this point, it's definitely "when," not "if." ®

https://www.theregister.com//2024/08/06/chrome_web_store_warns_end/