Google's Guide on Diagnosing Deindexed WordPress Site Post-Migration

The first step in diagnosing a deindexed WordPress site, as suggested by Google's John Mueller, is to analyze the data in the Search Console. This can help identify the exact date pages started dropping out of Google’s index and the reasons why they are no longer indexed, such as pages not being found (404) or being blocked from crawling by a robots.txt file.

To check if a WordPress site is blocking Google from indexing, you can use the Google Search Console. Look at the Page Indexing Report which will indicate if the site is blocked by a robots.txt file in the column labeled 'Why pages aren’t indexed'. Additionally, you can verify the robots.txt file directly by accessing it at example.com/robots.txt (replace 'example.com' with your domain) to see if there's an entry that blocks search engines.

If the 'Search Engine Visibility' setting in WordPress is causing the site to be deindexed, you should navigate to the WordPress admin panel, go to Settings → Reading, and locate the setting called 'Search Engine Visibility'. If the checkbox labeled 'Discourage search engines from indexing this site' is ticked, you should untick it to allow search engines to index the site again.

A WordPress site might be deindexed after migrating to a different web host due to several potential issues, such as:

• The new website is blocking search engines or Google specifically.
• There are robots.txt entries that are blocking search engines.
• A WordPress setting or plugin (like an SEO or migration plugin) may have been applied that blocks search indexing.
• Failure to update DNS settings to point to the new web hosting service.
• Issues on the web host side.

Investigating these issues starting with Google Search Console is recommended to diagnose the problem.