The website had noticeably fewer visitors than in the period it’s compared with. It’s worth finding out quickly whether the loss is real and where it came from.
What it means
Visitors are GA4 sessions. The issue explains what else moved: if search clicks fell too, it looks like a real loss of demand or rankings; if they didn’t, the drop is in other channels such as referral, paid, social or email.
What triggers it
It compares visitors over your comparison period (the last 28 days by default) with the period before, or with the same days last year if you compare against last year. The issue is raised when visitors fell by your “Visitors drop (%)” alert threshold (20% by default) or more, from at least 100. It is High, or Critical when the fall is twice the threshold.
For context it adds the change against the same days last year, the latest timeline note in the period and, when search clicks fell too, any broad Google update that rolled out then. It isn’t raised while a broken connection or GA4 tracking failure is open, because the numbers can’t be trusted.
Common causes
- Lost Google rankings, a Google update, or pages dropping out of the index.
- A paid campaign, newsletter, social post or referral link that ended, or that brought a spike in the earlier period.
- Seasonal demand, or tracking that only part of the website still carries.
How to fix it
- Open the website and compare its traffic channels and landing pages with the earlier period to find where the visitors went.
- If search fell, check the searches and pages that lost clicks and any recent content, redirect or technical changes.
- If another channel fell, check with whoever runs campaigns, email or social whether something stopped or changed.
When it clears
When visitors are no longer down by the threshold against the earlier period, either because they recovered or because the comparison has moved past the high point. Use the action’s “Since done:” figure to see whether your fix worked. See Using the action plan.