A broken link means a Web page or URL which cannot be accessed or found by website visitors and these links are also known as "link rot" or "dead links". These links will often show users errors while loading a page. These links will result in affecting rankings on search engines, increase bounce rate, and a bad user experience. So it is very crucial to detect these links and resolve them.
Below I have suggested some widely used broken link checkers tools:
1. Xenu’s Link Sleuth
2. W3C Link Checker
3. Google Search Console
4. Broken Link Checker for WordPress
5. LinkChecker