Google debuts ‘ad detection tool,’ letting marketers better assess ad experiences in Chrome

By Ronan Shields • September 15, 2026 •

Ivy Liu

In an era when website visits are tanking, primarily due to AI-overviews, evaluating the value of website visits, and the associated price of ad inventory is in flux.

And it’s within this context that Google – the entity which is concurrently the the largest provider of AIOs, ad tech offerings, and the industry’s most popularly used web browser (Chrome) – has made its latest announcement.

Google today announced new ad detection tools within its Chrome User Experience Report, or “CrUX,” geared towards helping paid-for media teams, both on the buy- and sell-side of the industry, better assess audiences’ ad-load experiences. “We’ve all encountered overwhelming ad experiences on the web,” reads a blog post, marking the launch, which expands on metrics already available within CrUX – see below.

Ad Count: The average number of ads in the viewport
Ad Density: The average percentage of the viewport area occupied by ads
Ad Weight (Network Usage): The resources consumed by ads measured in bytes
Ad Weight (CPU Usage): The resources consumed by ads measured in milliseconds

”We’ve heard from a large cross-section of ad ecosystem stakeholders that these metrics could enhance how they value web ad opportunities and make ad product decisions,” continues the blog post.

We look forward to exploring with the industry how these signals can improve quality and support advertiser goals

Bill Reardon, Google Ads

Google’s launch also contains supporting statements from across the spectrum of the ad industry, including agencies, publishers, and ad tech providers such as measurement partners and supply-side platforms.

This includes one from Bill Reardon, GM, enterprise platform, Google Ads, noting how its industry-leading demand-side platform is using CrUX. “Display & Video 360 supports this initiative to bring transparency to page layout quality. We look forward to exploring with the industry how these signals can improve quality and support advertiser goals,” he is quoted as saying.

According to Google it’s currently treating the four measurement criteria as experimental, and not treating CrUX assessments as part of its Core Web Vitals, with no recommended thresholds for what constitutes a good or bad ad experience at present.

How it works

Fielding follow-up queries from Digiday, Google offered further insight into how CrUX assessment works under the hood, noting how Chrome identifies advertising using a combination of network-level filtering and analysis of script execution.

For example, URLs matching its ad filter list can be classified as advertising, while Chrome can also identify resources or frames created by scripts it has already classified as ad-related. Chrome then samples the visible viewport once per second to calculate ad count and density. CPU and network consumption are instead accumulated over the user’s session, with CrUX ultimately reporting results at the 75th percentile.

Price-setting?

Additionally, aggregate CrUX ad reporting is restricted to sites with an ads.txt file containing at least one authorized seller, while single-page applications can accumulate measurements across multiple soft navigations. Chrome’s local DevTools measurements can therefore differ from the aggregated CrUX results.

Crucially, Google told Digiday that independent ad platforms will receive access to the data at the same time as Google’s own advertising businesses – this point is pertinent, given the pending remedies ruling in its ad tech antitrust trial.

However, it did not disclose whether DV 360 is currently testing the signals for inventory evaluation, bidding or reporting, with industry-watchers likely to question how quickly, if at all, CrUX metrics translate from transparency tooling into something that affects media prices.