Xenu's Link Sleuth

This is one of those indispensable tools for any web developer. Xenu's Link Sleuth is a nice, simple, easy-to-use, tool that will crawl any URL and report back on the status of every link. When it's finished you have the option to generate a report, or just look at the results grid.

(I used this on my site over the weekend... fixed a few dozen errors. So hopefully, nobody sees any broken internal links. External links, OTOH, I have not checked recently.)