Start with lost clicks, then ask why
Content decay describes a page losing search performance over time. A click drop can come from stale information, stronger competing answers, lower search demand or a change in how results attract clicks. It can also follow a migration or an indexing problem. The chart alone cannot tell you which explanation is right.
Use the content decay definition as a starting point. Keep an eye on absolute clicks as well as percentages: losing half of a tiny baseline may matter less than a smaller percentage loss on an important page.
How mowteng compares the periods
The insights_content_decay tool compares the last N days with the N days immediately before them. It finds pages that lost the most clicks and skips pages with fewer than 10 clicks in the earlier period. The cutoff keeps very small baselines out of this ready-made analysis; it does not mean smaller pages are healthy.
For seasonal content, use custom date range comparisons as another view. Ask for clicks, impressions, CTR and average position before choosing an explanation. Query, country and device breakdowns can show whether one audience accounts for most of the decline.
Questions for the first investigation
Which pages lost the most clicks in the last 28 days compared with the previous 28? Show both totals, absolute losses and percentage changes.
For the three biggest losses, compare queries, impressions, CTR and average position. Separate observed changes from possible explanations and suggest the next checks.
Match the action to the evidence
Falling impressions with broadly steady position may point toward lower demand or a different query mix. Falling CTR with similar visibility suggests reviewing how the page appears in results. A position decline calls for a closer look at intent, content quality and the queries affected. These are clues, not automatic diagnoses.
Inspect unexpected losses with an index coverage audit when a URL may have dropped from the index. Update facts, examples or missing answers when a content review supports it. Record what changed so you can assess the result later rather than rewriting every declining page at once.
Reproduce the comparison by hand
Open Search Console's search performance report and compare two equal date ranges. Review the pages table for click differences, then select a declining page and inspect its queries. Enable impressions, CTR and position and repeat by device or country where useful. Export the comparison to sort by absolute loss and exclude earlier totals below 10 if you want to mirror mowteng's cutoff.