In addition, there is a minor bug - if the file name contains the combination of digits 404, the link will be colored red, as if it's not working!

UPD: Works perfect after update. Thank you!

Awesome tool, helps to see the visual indication through the page...Great buddy, you done nice job.

This add-on is very useful for checking links in HTML pages and other files. It color codes the results for each link. You can tell if a link is broken, slow, insecure or working properly. It is compatible with Firefox Quantum. Very responsive customer service!
Highly recommend.

A broken link checker that works in Firefox Quantum! Thank you!