- Definition
- Observed visibility is the share of monitored searches in which a domain showed an ad.
In plain words
If you checked a search 100 times and a domain's ad appeared in 40 of those checks, its observed visibility is 40%.
It answers one simple question: in the searches we looked at, how often was this advertiser there?
Why it matters for brand and paid search teams
Teams need a number that compares advertisers fairly across keywords, places and devices, without access to anyone else's account. Observed visibility gives that for every domain, including competitors and partners.
It is also easy to misread. Shown without a label next to impression share or clicks, it can lead to wrong conclusions in a client report or a legal brief. The definition matters as much as the number.
How it works
The numerator is the number of completed checks in which the domain showed at least one ad. The denominator is the number of completed checks in your selection of keywords, locations, devices, engines and dates. Failed or pending checks are gaps, not zeros, and stay out of both.
Google's impression share is a different measure: the impressions an advertiser received divided by the impressions it was estimated to be eligible for, calculated from the advertiser's own auctions. Only the advertiser can see it. The two numbers answer different questions, so label them separately.
Example
Northstar monitors 5 keywords in 3 US cities on 2 devices, twice a day, on Google. Over 7 days that is 420 completed checks. summit-outdoors.example appeared in 126 of them, so its observed visibility is 30% for that selection.
Filtered to mobile in Austin only, the same domain shows 55%, because the competitor concentrates there.
Fictional brands and domains, for illustration only.
Common mistakes and misconceptions
Observed visibility is the competitor's impression share. It is a share of your monitored sample. Impression share comes from the advertiser's own auctions and is private to them.
A higher number means more spend. Visibility shows presence in your checks, not budget or clicks.
Numbers from different filters can be compared directly. The denominator changes with the selection. Compare like with like, and say which keywords, places and dates you used.
How to monitor it in Ads Lighthouse
The Visibility column in Paid results and the advertiser reports uses this definition. It follows your filters and date range, including engine, device, operating system, country and location, and carries into CSV and Excel exports.
Ads Lighthouse labels it as a sample measure and never presents it as impression share.
Because it is built from checks you control, you can widen or narrow the sample on purpose: add cities or devices to see more of the market, or filter to one search to answer a specific question from a partner or client.
Frequently asked questions
Why is visibility different from what I see in Google Ads?
Google Ads reports impression share from your own auctions. Observed visibility counts how often a domain appeared in the searches Ads Lighthouse checked for you.
Do failed checks count as zero?
No. Only completed checks are counted. A check that failed or is still pending is a gap in the sample, not an observation with no ads.
Can I report visibility to a client?
Yes, with its definition: the share of monitored searches, for the listed keywords, places, devices and dates, in which the domain showed an ad.
Official sources
- Google Ads Help: Get impression share data
- Google Ads Help: Use auction insights to compare performance
Sources checked on .