What to check when a site moves.
WHAT BREAKS MOST OFTEN
The search engine visibility setting, carried from a staging site URLs changing without redirects The sitemap not regenerated Robots.txt carried from development, blocking everything HTTPS not configured Structured data lost
THE FIRST CHECK
The visibility setting. Immediately.
THE SECOND
Load your robots.txt and read it.
A development robots.txt blocking everything is a common and severe migration fault.
WHAT ELSE TO VERIFY
Every URL still resolves, or redirects The sitemap loads and is current Search Console still verified HTTPS works across the site
FOR A PLATFORM CHANGE
URLs almost certainly change.
Map every old address to its new equivalent and redirect.
WHAT TO MONITOR AFTERWARDS
Indexed page count Traffic against the previous period Not-found errors
WHAT A SUSTAINED DROP MEANS
Something broke. Investigate rather than waiting.
HOW LONG FLUCTUATION IS NORMAL
A week or two. Beyond that, investigate.