Open and use the Web Part Maintenance Page

Referred Link - https://support.office.com/en-us/article/Open-and-use-the-Web-Part-Maintenance-Page-eff9ce22-d04a-44dd-ae83-ac29a5e396c2

Purpose
This following tip help you for opening Webpart maintenance page and list out all web parts in the page.

Resolution
To access the Web Part Maintenance Page for a page that is not stored in a document library, such as the site home page, append Contents=1 to the end of the URL for the page..

Example
http://testsite/sites/AlcoaDemo/_layouts/15/spcontnt.aspx?&url=%2fsites%2fAlcoaDemo%2fSitePages%2fCommunity%2520Home.aspx

to
http://testsite/sites/AlcoaDemo/_layouts/15/spcontnt.aspx?&url=%2fsites%2fAlcoaDemo%2fSitePages%2fCommunity%2520Home.aspx?Contents=1