Canonical URL Checker - Inspect Canonical URL HTML Tag
Canonical Tag inform SE about "preferred" or "Original" Content
Canonical URL Checker tool inspect Canonical HTML Tag of webpage. Canonical URL is a communicating medium to Search Engine. Canonical Tag of a web page tells Search engine which is "preferred" or "Original" Link and Prevent duplicate content issues in search engine optimization/SEO.
If the current page URL and Canonical URL are same, it means the current page is preferred & Original webpage for Search Engine Indexing & It should not exclude from Indexing.