HTML and website link validators

• W3C® Link Checker: free online service that validates HTML and internal website links.
• Xenu's Link Sleuth: free downloadable program that validates all links within a site. Fast, useful and comprehensive.
• HTML Validator lite: free version of HTML Validator. Professional version available. More complex and less user-friendly than Xenu.

See also:

• AnyBrowser.com: browser compatibility issues. Includes link and html validity checker.

Testing your site

Search engines and meta tags