What to do when your rankings suddenly drop dramatically?
First of all: Don't panic.
Dropped Rankings Cheatsheet / Checklist.
Check Your Rank Tracker.
Did your rankings really drop?
Double check whether this is really the case, or that your rank tracker is acting up.
Check Impackted Sections.
Check what website sections were impacted by the ranking drop using Google Search Console, Bing Webmaster Tools and web analytics software.
Check for Google Penalty.
Are your pages still indexed?
Are you still ranking for non-branded queries? Also check your Google Search Console.
Check if you have been hacked.
Check if you were hacked using the guides and tools from Google and WordFence.
Check for Google Updates.
Check SEO news sites for recent Google updates, as well as Rank Trackers that keep track of volatility in SERPs.
Check your log files.
Check if search engine crawlers are crawling less frequently, encounter errors or get slow responses.
Check your competition.
Check if your competition made their move and took over your website in the SERP.
Check lost backlinks.
Use Ahrefs or Majestic to discover whether you lost any backlinks recently.
Check disavowed backlinks.
Check if some backlinks were recently disavowed. It could be that these actually packed a punch.
Digital Marketing on demand.