Hi
As mentioned by Scott,
We can use:-
1. The External Link Checker
Link:- https://docs.adobe.com/docs/en/aem/6-2/administer/operations/external-link-checker.html
//An external link checker is provided within CQ. The link checker:
scans all content pages
generates a list of all valid and invalid links
marks invalid links as broken in situ on the individual content pages
2. Linkchecker is a Sling rewriter. Rewriters are strictly associated with the request. They operate on the HTML code generated by the CQ before it's returned to the client. If I understand correctly, you want to look for broken internal links in the whole site and the Linkchecker won't be very useful here.
Consider using Groovy console to crawl over the /content/your_site looking for strings starting with /content. Then use resourceResolver to check if the found path exists. Sample script implementing this algorithm can be found here.
Also there exist free online tools to check broken links:-
Link:- http://www.brokenlinkcheck.com/broken-links.php
Link:- www.deadlinkchecker.com
I hope this will help you.
Thanks and Regards
Kautuk Sahni