Hi machiner,

There are a couple scripts floating around that will report whether a Div gets filled or not. Try some web searches. I think I even posted a simple php version here a couple years ago.

The original purpose of these scripts was to catch adblockers and trigger alternate ads to fill the Divs.

However IMO it just adds more processes to the webpage and demotes Page Speed score, which is why after the initial curiosity, I removed mine.

Hello, sometimes i notice that i open my website and i don't see ads.
how can i know how many times it happening?

Look at the "coverage" metric in the Adsense dashboard. This value tells you how often the Adsense code was successfully executed but did not render an ad.

Ad blockers are preventing the loading of the adsense script, so blocked ads are not counted in the coverage stats.

That's why it isn't an accurate indicator of how many ads don't load for all site visitors.

machiner doesn't ask about ads being blocked. He (she?) mentioned that when he is visiting his own site, he noticed sometimes ads are not showing. So his concerns were not about ad being blocked by "others". Also the title of his topic is to know how much ads "Google is not showing", so his question is about ads not being served, and not ads blocked.

Additionally, (and if it's effectively about ads not being served, and not ads being blocked), you can set up back up ads , and look how often your backup page is hit.

Point is, the Adsense panel tools are inaccurate and misleading. Missing ads is just one of its report shortcomings.

Hey everyone thanks for the answer,Travis is right, that is my question.

how can i know how many times google does not show my ads? as Travis said.
and how can i add backup ad from google?