In a zero-click search, the answer is already in the search results. Think of a featured snippet with the answer at the top, an AI Overview, a shop’s opening hours or the weather. The searcher has enough information and does not click through. Zero-click has no official definition; it describes search behaviour.
Why does it matter?
Your page can be seen without a visit following. In Search Console, an impression counts each time your site appeared in the search results, and a click each time someone clicked through. The click-through rate (CTR) is the number of clicks divided by the number of impressions, according to the Performance report documentation.
How do you check it?
Open the Performance report in Search Console and look at impressions and clicks per query. A query with many impressions and few clicks can indicate that the answer is already in the results. Search for the query yourself and see what Google shows above your result.
Common mistake
Blocking text snippets to force visitors to click through. According to Google, nosnippet removes both featured snippets and regular text snippets. That does not make your result more attractive. Make sure your page offers more than the short answer.
See also SERP and AI Overviews and AI Mode.