Why do my Google Ads campaigns have clicks but no sessions in GA4?

If it’s literally zero sessions, it’s usually a tracking or attribution setup problem, not just normal reporting noise. First check that the Google tag loads on every real final landing page, the Google Ads account is linked to the right GA4 property, and auto-tagging is on. Then paste a final URL into a browser with `?gclid=TesTER-123` added and follow every redirect; that parameter needs to survive unchanged. If a redirect, URL rewrite, consent setup, or landing-page error strips it or prevents the tag from loading, Ads can count the click while GA4 records no usable session. Also compare the same dates and give a new link up to 48 hours. Small gaps are normal because Ads counts clicks while GA4 counts sessions, and someone can leave before the tag runs. But a whole campaign showing clicks and zero sessions is a pretty strong sign to start with the landing-page tag and GCLID test.