Chrome devs change draft rule that would thwart adblockers

Google is rolling back some of the draft requirements of its Chrome Extension Manifest V3. It concerns a limit of WebRequests that an extension may submit. According to the Chromium team, this was supposed to maintain performance, but would also thwart ad blockers.

Google posted the document in November last year, prompting discussion in the developer community. Raymond Hill, developer of uBlock Origin, argues that the limit would not even be enough to enforce just the well-known EasyList and that these regulations mean that uBlock Origin ‘could no longer survive’.

The motivations were privacy and performance, but the respondents disagreed with the latter. A limit on api calls for WebRequest would seriously hinder ad blockers, but they found no noticeable performance gains. This includes the developers of Ghostery, who in response researched the effects on browser performance when using content blocking.

For the study, they took a closer look at uBlock Origin, Adblock Plus, Brave, DuckDuckGo, and Ghostery themselves. In a nutshell, the Ghostery devs state that all of these ad blockers, except DuckDuckGo, took less than a millisecond per request to decide whether to block or not. With an average of twenty percent of all requests blocked on a web page, this amounts to negligible influence according to the developers.

The Chrome developers seem to think the same on closer inspection. On Friday, the day the investigation was posted online, Devlin Chronin posted on the Chromium website that “our goal is not and never will be to thwart content blockers.” The limit of 30,000 calls will be increased, but a limit is still necessary, according to the Chromium team, because block lists such as EasyList only grow and outdated rules are not removed.