Google Chrome's Native Ad Blocker Detailed Ahead of Launch on Thursday

Google on Tuesday reiterated that Chrome's native ad blocker would roll out on Thursday, February 15. It also detailed how the ad blocker - what it calls an 'ad filter' - would work. While it will not look to block all the ads on websites, it will prevent webpages from displaying "disruptive ads" even after they have been flagged. These may include ads that pop up on the entire screen as well as auto-playing video ads. The guidelines are in sync with the Better Ads Standards set up by the Coalition for Better Ads, which Google Chrome joined last year.

Announced in December last year, the Better Ads Experience Program aims at certifying certain Web publishers that post ads compliant with its standards. Browsers and advertising technology companies will be accredited to assess publisher compliance in the program. Non-compliant publishers are expected to have their ads suspended for a period of 30 days. Tools like Ad Experience Report have previously been made available to publishers aiming to comply with the Better Ads Standards.

"It's important to note that some sites affected by this change may also contain Google ads. To us, your experience on the Web is a higher priority than the money that these annoying ads may generate-even for us," said Rahul Roy-Chowdhury, Vice President, Chrome clarifying Google's take on creating a balance between consumers, content producers, hosting providers, advertisers, Web designers, and other players on the Internet.

Ad blocking will be enabled by default on both desktop and mobile. Users can choose to switch it off by going into Chrome Settings > Content Settings > Ads.

Google in a Chromium blog post on Wednesday reiterated it would block ads that do not follow the Better Ads Standards guidelines, and also presented more details on how Chrome's ad filtering works. It said that while some of the ads that violate the standards have intrinsic problems, in other cases, the problematic experiences are the fault of the site owner - displaying high ad density or prestitial ads with a countdown. The company said it thus evaluates how well sites comply with the Better Ads Standards, informs them of any issues encountered, and then block ads if the sites don't proceed to comply.

12 ad experiences that research found to be particularly annoying to users, as per Coalition for Better Ads

Site evaluations are done by examining a sample of pages from the site, said Chris Bentzel, Engineering Manager at Google. Depending on the number of violations, sites will be awarded Passing, Warning, or Failing statuses. Developers will be able to access their evaluation on the Ad Experience Report API page. They can request for a re-evaluation once they believe they have fixed the offences.

When browsing, Chrome's ad filter will first check if the particular webpage the user is on belongs to a site that has failed the Better Ads Standards. If it has, Chrome will check network requests on the page against known ad-related URL patterns (based on public EasyList filter rules), and block them - preventing the ad from being displayed. These ad-related patterns can include Google's own platforms - AdSense and DoubleClick.

If at least one network request by the site is blocked, Chrome will inform users that ad blocking has occurred on that site, and also give them the option to "allow ads on this site" if they so prefer. On desktop, the ad blocking notification is said to look similar to Chrome's existing pop-up blocker. How it will look on Android can be seen above.

"While the result of this action is that Chrome users will not see ads on sites that consistently violate the Better Ads Standards, our goal is not to filter any ads at all but to improve the experience for all web users. As of February 12, 42 percent of sites which were failing the Better Ads Standards have resolved their issues and are now passing. This is the outcome we are were hoping for — that sites would take steps to fix intrusive ads experiences themselves and benefit all web users. However, if a site continues to maintain non-compliant ad experiences 30 days after being notified of violations, Chrome will begin to block ads on that site," Brentzel adds.