Web Site Garage http://www.WebSiteGarage.com/ : Offers a free tune-up that includes a 5-point checkup to diagnose common Web site design and promotion mistakes. This includes Load Time Check, Site Popularity Check, HTML Design Check, Spell Check, and Dead Link Check. GIF Lube can reduce the file size of your image so that your page can load faster.
Net Mechanic http://www.netmechanic.com/ : Robots will search your site to find broken links, spot bad HTML tags, and rate your server's response time.
Meta Builder 2 http://vancouver-webpages.com/VWbot/mk-metas.html : This form will generate HTML META tags suitable for inclusion in your HTML document. These tags allow better indexing by robot-driven search engines, such as AltaVista, Infoseek and searchBC, and now includes some DC.lite elements.
WebTechs Validation Service http://www.webtechs.com/html-val-svc/ : Supply the URL of a page anywhere on the World Wide Web and the Weblint program checks your HTML code for you.
Dr. Watson http://addy.com/watson/ : Dr. Watson is a free service to validate your web page on the Internet. You give it the URL of your page and Watson will get a copy of it directly from the web server. Watson understands the latest HTML 3.2 standards, as well as Netscape and Microsoft extensions up through version 4. Watson can also verify that the links on your page work, as well as spell-checking your text.