WP-LinkCheck is a lightweight plugin ability to check all image sources are broken inside your WordPress blog.
According to different sources will be on different location (server),if the server response times is slow, WP-LinkCheck will take more times to verify,but it no longer then 5 seconds, WP-LinkCheck default set 5s to timeout,after 5s and server has no response,it mark the url as bad.
WP-LinkCheck is safe to use, it will not modiy or delete any content inside your blog.If it's found broken link, you can click the Blog title ,it will open a window allow you modify the url as you like.
The only foot print is WP-LinkCheck need to write one line to WP database's options table , this line named : [wp_linkcheck_options]. Simply delete that line after deactivate.
Because i come from HongKong , I speak Chinese :)