W3C link checker is a highly recommended link checker. It checks the website and its component such as hypertext links for both HTML and XHTML format; if it is working properly. It is important that a website contains high technical quality. W3C link checker will generate the following reports:
CSS style sheet and extracts a list of anchors and links
It checks that no anchor is defined twice.
All the links are dereferenceable
Warns about HTTP redirects
You can check your URL at W3C Link Checker and you will have to check through this form.
When it is in summary mode, it may take time for loading process. When the checking is done, it will show you “List of broken links and redirects” if broken links were found. You have to go through the pages, fix the broken link or if unresolvable it would be better to delete it. However, the link checker considers robots exclusion rules. When the robots.txt files of the website disallow link checks, there will be no single information from the website that will be seen.
Ref : W3C link checker in SEO