Big changes coming to Chrome may kill ad blockers

In a recent blog post, Chrome extensions and web store product manager David Li announced that extensions to Google's browser built using the Manifest V2 specification will no longer be accepted on the web store as of January 17, 2022. Furthermore, Manifest V2 extensions will be disabled altogether in January 2023, so any that you have installed will no longer function.

"Years in the making, Manifest V3 is more secure, performant, and privacy-preserving than its predecessor," Li wrote. "It is an evolution of the extension platform that takes into consideration both the changing web landscape and the future of browser extensions."

It's also a big deal for a very different, and for many Chrome users much more practical, reason: As TechRadar explains, the loss of Manifest V2 means that the ad blockers many Chrome users have grown used to having around will no longer work. Manifest V3 deprecates a particular API that current ad blockers use to do their thing, and there's debate over whether new ad blockers can or will be built using the new Manifest V3 specification.

Google said in a 2019 Chromium blog post that disabling ad blockers is "absolutely not the goal" of the new spec. "In fact, this change is meant to give developers a way to create safer and more performant ad blockers," Chrome extensions developer advocate Simeon Vincent wrote at the time.

In a 2018 SEC filing, however, Google parent company Alphabet explicitly warned that ad blocking technology, both existing and new, have the potential to harm its business.

"Technologies have been developed to make customizable ads more difficult or to block the display of ads altogether and some providers of online services have integrated technologies that could potentially impair the core functionality of third-party digital advertising," the filing states. "Most of our Google revenues are derived from fees paid to us in connection with the display of ads online. As a result, such technologies and tools could adversely affect our operating results."

The Electronic Frontier Foundation also took issue with Google's claims, saying in a 2019 statement that while the Manifest V3 standard may not be aimed at killing ad blockers specifically, it could easily happen as a side effect of limits the new API will put on developers.

"For developers of ad- and tracker-blocking extensions, flexible APIs aren’t just nice to have, they are a requirement," the EFF wrote. "When particular privacy protections gain popularity, ads and trackers evolve to evade them. As a result, the blocking extensions need to evolve too, or risk becoming irrelevant ... If Google decides that privacy extensions can only work in one specific way, it will be permanently tipping the scales in favor of ads and trackers."

Senior staff technologist Alexei Miagkov, who co-authored that post, told The Register that the EFF's position on the new Manifest V3 standard, and Google's justification for it, hasn't changed. "Our criticism still stands," he said. "The reasons they have stated publicly [for this transition] don't fully make sense."

Google said that further details about the move to Manifest V3 in Chrome will be shared closer to the rollout date, and promised to continue adding new capabilities to it "based on the needs and voices of our developer community." A detailed timeline on the Manifest V2/V3 changeover is available on the Chrome Developers site.

Even if Google does kill off ad blockers as we know them in Chrome, extension devs will likely find workarounds to keep avoiding ads. And if they can't, well, a whole lot more people are going to start learning about Pi-holes.