Does a website link (href) validation service exist?

I am looking for a web service kind of like Google Analytics. Paste some javascript into your web page and if any of the links there become invalid, hey presto, an email is sent to someone telling them w开发者_如何学Chich link, which page etc etc has the incorrect link.

Anyone heard of such a service?

This would slow the page loading down a lot if it had to check for broken links every time someone visited it (basically a http request for every link). Not that it isn't possible, but the implementation would have to be very very good.

Javascript cannot send emails, you would have to use ajax to post the details to another page that would then email the admin. As this is all client side, it is very open to abuse.

I would suggest using a program to do it every now and again. There are even Firefox extensions to do it rather than a program. Google will also list a whole host of websites offering the service.