Display ad impression totals will fall for publishers using Google AdSense and Google Ad Manager beginning February 17, 2027. Google notified AdSense publishers directly via email on September 1, 2026, and published a companion Help Center article confirming that both platforms will switch display impression counting from the count-on-download (COD) method to the begin-to-render (BTR) standard on that date.
What the Methodology Change Means
Google Ad Manager and AdSense currently use a count-on-download methodology for display inventory, recording an impression when the ad server responds to a request and the creative asset begins downloading to a user's device. The shift means display ad impressions will only be recorded once an ad creative has successfully loaded and started to render on a user's device, rather than when the ad merely begins downloading.
Under the current COD method, impressions are counted for ads that begin loading on a page but may never fully render, for example, if a user navigates away before the ad finishes loading. Those impressions will no longer be counted under BTR.
Which Inventory Types Are Affected
The change applies specifically to display banner inventory across web, mobile web, and connected TV (CTV). According to Google's Help Center documentation, Ad Manager and AdSense already use or are compliant with begin-to-render for native, app, and video inventory impression counting, and the shift to BTR for display ads unifies the impression counting methodologies across all inventory types. Banner display had remained the last inventory category still operating on the count-on-download standard.
Industry Standard Alignment
Google has framed the transition as an alignment with broader industry requirements. In accordance with Interactive Advertising Bureau (IAB) and Media Rating Council (MRC) guidelines, an impression under BTR is only logged once the creative successfully loads and starts visibly rendering on the actual physical user device. By adopting BTR for display inventory, Ad Manager will use a unified counting methodology across all its inventory types, matching the approach already used by demand-side platforms and third-party measurement providers.
Display and Video 360 moved display impression counting from on-download to begin-to-render in September 2025, and Campaign Manager 360 followed in November 2025. The February 2027 date brings AdSense and Ad Manager's publisher-side display counting into alignment with those buy-side platforms.
Expected Impact on Publisher Metrics
The change is expected to result in lower reported impression numbers for publishers. Google has stated that publishers "may see a change in total impressions," attributing the drop to the exclusion of ads that began downloading but never rendered on a user's screen. Impressions recorded via begin-to-render are more likely to have had a tangible opportunity to be seen, though publishers can expect a slight decrease in overall impression volume as a result of the stricter counting method.
Google has also noted the change should reduce discrepancies between Ad Manager impression counts and those reported by buyers or third-party measurement vendors.
How Publishers Can Estimate the Impact
Google has recommended that Ad Manager publishers run reports to estimate the potential difference between their current COD and future BTR impression counts by creating an interactive report in Ad Manager that compares "Ad server impressions" (currently using COD) against "Ad server begin-to-render impressions." Google advises using a historical report with a start date no earlier than August 12, 2026, for the most relevant comparison data.
Lazy Loading and Creative Optimization Considerations
Google's Help Center documentation notes that lazy loading and lazy rendering settings affect BTR measurement directly, because they determine when creative assets begin rendering in the user's browser. Publishers can raise the `renderMarginPercent` or `fetchMarginPercent` values to cause assets to render earlier in the user experience. Google has cautioned, however, that these settings also increase resource demands on the publisher's network and the end user's device, and publishers should weigh the trade-offs before making adjustments.
MRC Accreditation and Publisher Action Required
Google has confirmed that Ad Manager will continue to retain MRC accreditation for display, video, and rich media creatives within desktop, mobile web, and mobile application environments following the transition. The company has told publishers that no action is required on their part, and the switch will take effect automatically on February 17, 2027.
Practical Implications for Publishers and Advertisers
Publishers monetizing through AdSense or Ad Manager display inventory should treat any post-February 17, 2027 decline in reported impressions as a reporting correction rather than a loss in actual ad delivery. Advertisers buying display inventory through these platforms may see improved impression quality signals, as counted impressions will more reliably reflect ads that reached a user's screen. Publishers who benchmark performance month-over-month should document the methodology change date to avoid misattributing the shift as a traffic or revenue anomaly.
Google's Help Center article on begin-to-render impression counting for display ads, published alongside the direct publisher email notification, states that additional reporting metrics, including "Ad Exchange begin-to-render impressions" and "Total begin-to-render impressions," are forthcoming and will be available to Ad Manager publishers ahead of the transition date.
