Google Chrome will block “heavy” ads

August 2020

Back in May 2019, Google announced its new ‘heavy ad intervention’ feature which aimed to block ads that consume a disproportionate amount of resources and negatively impact the user experience.

To reiterate, ads are considered as ‘heavy’ if a user has not interacted with it and it meets any of the following criteria:

• Consumes more than 4MB of network bandwidth
• Uses CPU for 15 seconds or more in any 30 second window
• Uses CPU for 60 seconds or more in total

Any ads that are deemed as too resource-heavy will be automatically be unloaded by Chrome. According to the tech giant, only 0.3% of ads exceed these criteria, but they do, however, account for 27% of network data used by ads and 28% of all ad CPU usage.

Although Google initially had not confirmed when the changes would go live, it has now been confirmed by a Google developer on a Chromium message board that full launch will commence in late August 2020. As Chrome 85 is set for release on Tuesday 25th August, there is some speculation that heavy ad intervention will coincide with this.

The impact will be limited for ad tech companies that have already reduced bandwidth and CPU usage in their ad units. However, publishers that still monetize using long-form video and rich media ads are likely to see a negative impact on revenue.

Publishers can test how heavy ad intervention will impact their pages in Chrome or learn how to handle heavy ad intervention here.

November 2019

Google has now added the “Heavy Ad Intervention” feature to the most recently updated Canary version of its Chrome web browser. The feature is experimental and can be enabled easily by following these steps:

1. Download and install the most recent version of Google Chrome Canary
2. Type ‘chrome://flags’ into the address bar
3. Search for ‘Heavy Ad Intervention’ and enable the feature
4. Once enabled, you will need to restart Google Chrome.

July 2019

A commit note, marked as work in progress on Chromium, suggests that Google Chrome will soon introduce a “Heavy ad intervention”. The change looks to target iframes that use excessive bandwidth or CPU resources.

Implement Heavy Ad Intervention

This change introduces a feature that unloads ad iframes that have been detected to use an egregious amount of system resources. This reuses the quiet safe browsing interstitial UX, which gets loaded into the ad iframe. This intervention unloads ads that are in the .1% of bandwidth usage, .1% of CPU usage per minute, and .1% of overall CPU time. The current numbers are 4MB network and 60 seconds CPU, but may be changed as more data is available. The intervention is implemented as an error page loaded from the browser process. This is triggered from AdsPLMO.
[source]

This change would seem to be targeting heavy video creatives and possibly those using bad tactics like crypto mining. The “intervention” would be to block the creative and replace it with a notice that the ad was blocked. This is a very different approach to Chrome’s “bad ads blocking” that blocks all ads on the domain.

Given that few publishers want resource-intensive ads slowing user experience and driving traffic away from their sites, this change is likely to be well received. It certainly seems to be aimed more at those distributing bad creatives than the publishers who unknowingly deliver them.

There is no mention of when this change is likely to enter public release. Subscribe to our monthly newsletter to follow this, and other news that impacts web publishers.

This article was originally posted on July 5, 2019 and has since been updated regularly to reflect the most recent changes. We intend to continually update this as we become aware of any developments.