Broken Links are those links which show a 404 not found error. From an seo point, broken links should not be present on a website as it degrades the user experience. Many webmasters make the mistake of keeping lots of broken links on their website without knowing this may be harmful from seo point of you.
How to check broken links ?
You can check broken links manually but it is recommended to use software as it may help in finding out broken links in an easier way. Some of the popular broken link checkers are given below:-
Broken Link Checkers
Broken link checker
Iwebtool broken link checker
Roundcube
W3C linkchecker
Xenu link checker
Submit express link checker
Seoranksmart link checker
SSW Link Auditor