Google's numbers
Four checks read from Google Search Console once a day. Each finalised day's clicks or impressions are compared with the median of the same weekday over the previous eight weeks, and called within or below its normal range. Three or four days below in a row open one incident, which closes when the numbers come back. A spike is never an alert, and a site too small to judge never hears from this group at all.
How a day is judged, so you can redo the sum
Take the day's number, and the same weekday on each of the previous eight weeks. Weekdays are matched because a business site routinely loses half its traffic at weekends, and a plain average would call every Saturday a collapse.
Leave out any of those days that Google lists as a data anomaly, and any day when an incident for the same check was already open, so a long drop can never become its own normal. If that leaves fewer than eight, reach back one more week at a time.
The normal level is the median of what is left: one viral day cannot raise the bar for weeks. The day is below when it is under 70 percent of that level for site clicks and impressions, or under 60 percent for a page's clicks. Fewer than five usable days, or a normal level under the floor (30 clicks or 300 impressions a day for a site, 10 clicks for a page), is too little to judge, and nothing is recorded.
These numbers belong to the check, not to your account. Every evidence block shows the day, the value, the normal level, the drop and every date used or left out.
Slower than the page checks, on purpose
Google finalises a day two to three days late, and a drop has to hold for three days. A drop that starts on a Monday is reported on Friday or Saturday at the earliest. When the cause was a change on the page itself, the page checks will usually have told you days earlier.
When most of the sites CrawlWarden watches drop on the same day, the date is held and checked against Google's own reporting notices before anyone is told. One reporting fault at Google must never become an email to every customer at once.
What it does not catch
A slow decline over months. The normal level slides down with the traffic, so a site losing two percent a week for twelve weeks stays within its range throughout. This group catches drops, not erosion.
There is no check on average position. Google's average position moves when a site starts ranking for new, weaker queries, which is good news that reads as bad. It is shown as evidence, never judged.
All 4 checks in this group
Site clicks
on by default · · confirmed over 3 runs
Google's clicks for the site fell below their normal range.
Google's clicks for the whole site stayed below their normal range for three finalised days in a row. The usual causes are a ranking loss, a deindexed section or a broken template.
Site impressions
on by default · · confirmed over 3 runs
Google's impressions for the site fell below their normal range.
The site appeared in fewer Google searches than normal for three days in a row. Impressions fall before clicks do, and fall even when nobody was clicking.
Page clicks
on by default · · confirmed over 4 runs
Google's clicks for the page fell below their normal range.
Google's clicks for one watched page fell below their normal range for four days in a row. Confirmed over one more day than the site checks, because a single page moves more.
Click through rate
off by default · · confirmed over 4 runs
Clicks fell while impressions held: fewer searchers chose the result.
Off by default. Clicks fell while impressions held: the site was shown as often, and fewer searchers chose it. Usually a title or snippet that changed, or a competitor that appeared above it.
Every check on this page is available on every plan, including the free one - limits are on sites and URLs, never on checks. CrawlWarden pricing, per site rather than per URL.