Step 1: Confirm the drop is real
Open Search Console > Performance and compare the last 28 days to the previous 28 days. Filter to the affected pages or queries. Distinguish between an impressions drop (visibility issue) and a clicks-only drop (CTR issue, often a SERP layout change).
Check the date the drop started. If it aligns with a known Google update (semrush.com/sensor or moz.com/google-algorithm-change), it's algorithmic. If it's a unique date, it's a site-side change.
Step 2: Check for technical changes
Look at every code or content deploy that happened in the 7 days before the drop. The top culprits: an accidental noindex on the affected pages, a robots.txt that blocks the crawler, broken canonical tags pointing pages to other URLs, or a redirect chain longer than 3 hops.
Use Search Console's URL Inspection tool to confirm the page is indexed and has the correct canonical. Use Screaming Frog to crawl the affected section and find any unintended directives.
Step 3: Check Manual Actions and links
In Search Console, check Security & Manual Actions. A manual action is rare but devastating — it requires fixing the underlying issue and submitting a reconsideration request.
Check your backlink profile in Ahrefs or Semrush. If you lost a high-authority link recently (e.g., a major news mention got removed), it can affect related rankings.
Step 4: Check the SERP itself
Search the affected query in an incognito window. If a new competitor has appeared at #1, study what they're doing differently — usually fresher content, better schema, or a stronger E-E-A-T profile.
If the SERP layout changed (more ads, AI Overviews, a new map module), the organic real estate may have simply shrunk. The fix is content depth and schema, not panic.