AdSense Impressions vs. Page Views and Viewable Impressions

An AdSense impression does not mean that a user actually saw an ad. Google counts an impression for each ad request in which at least one ad began downloading to the user's device. Google, “Impressions”

Separate three metrics

For ordinary display inventory, Google explains viewability as at least 50% of the ad area on screen for at least one continuous second. Active View reporting

Why page views times ad units may not match

• Ad code did not execute.
• A blocker or browser setting prevented a request.
• Navigation occurred before loading.
• Auto ads placed different formats by page or device.
• Invalid activity was removed.
• Date ranges, time zones, or filters differ.

Google also lists non-executing browsers and crawlers, multiple ad units, and invalid activity as reasons publisher statistics can differ from AdSense. Report differences

Diagnostic order

1. Align date range, time zone, and page scope.
2. Inspect ad code and network requests on the rendered page.
3. Break reports down by ad unit, Auto ads, and device.
4. Use Active View to separate downloading from potential visibility.

Do not explain a revenue change from impressions alone. Compare page views, requests, coverage, and estimated earnings over the same period.

Takeaway

An AdSense impression is based on an ad beginning to download. It is not proof that the ad was viewed. Do not expect a fixed page-view ratio; use Active View for viewability and earnings metrics for revenue.