Shawn Hooper

This plugin generates a list of all the custom page templates available in the active WordPress theme, and shows you how many pages use this template. 
It will also show you if the page contains any Gutenberg blocks or not.
You can also click on the count to access the list of pages that use a specific template.

Page Template Usage Info

Shows you which pages are using which templates, and whether or they are built with Gutenberg or not.

Jeremy Edmiston

WP-Audit was initially built to provide a detailed audit report of potential client sites. The initial goal was to get as much information about current environment, database, themes and plugins to ensure compatibility within a managed hosting envrionment and for capacity planning.
WP-Audit is part of a full suite of client monitoring and systems health tools currently under development at https://wpsystemcenter.com/

​WP Audit

Provides audit data for site health and client reporting

Page Template Usage Info vs ​WP Audit

Page Template Usage Info vs WP Audit