GA4 recorded no visitors at all on some recent days, although the days around them were normal. Totals for any period that includes those days are lower than the real figure.
What it means
A busy website almost never has a day with nobody on it. A day of zero between normal days means GA4 wasn’t collecting, not that visitors stayed away. GA4 can’t fill those days in later.
What triggers it
It looks at GA4’s daily visitors over the last four weeks. On a website with a median of 20 or more visitors a day, it raises this Medium issue for any day with zero visitors after the first day that had some, and lists up to five of the dates. The last 3 days are left to the GA4 tracking check.
Common causes
- The tag was removed or broken by a deploy, then put back a day or two later.
- The website was down, or showing a maintenance page without the tag, for the whole day.
- The GA4 property or data stream was paused or edited, or the tag pointed at another property for a while.
How to fix it
- Check what changed on the website, its hosting or its tag setup on those dates, and make sure it can’t happen again.
- Confirm in GA4 that those days really show no data, and that tracking works today.
- Add a timeline note on the first missing day so charts and reports explain the gap. See Timeline notes.
When it clears
When the empty days are more than four weeks old and drop out of the check. Until then it’s still detected even after the cause is fixed, because those days stay empty.