Link rot kept biting me on big sites, so I built Broken-Links Scanner.
Highlight any part of a page, hit scan, and it checks just those links. Free, no tracking.
Chrome Web Store → https://chromewebstore.google.com/detail/broken-links-scanner/jcfgjohakfnckffjncgfmoldibhbmofm
More info → https://linkscan.app/ · dev log → https://koval.dev/blog/broken-links-scanner/
Give it a spin and let me know what you find.