Other than submit individual web pages for verification on the W3C site, are there any standalone tools that will do this job.
Ideally this would be a visual studio plugin that could catch errors at design time but one that would just take a wep application url running locally would be good.
Open source suggestions would be preferable
The W3C Markup Validator is an open source tool, which you can download and use it offline.
On Fedora, do:
yum install w3c-markup-validator
I use the FireFox plugin "HTMLTidy" to do this. When you are testing, you can point Firefox to your dev server (i.e. "http://localhost:52457/...") and it will work as if the site were live.
Also consider setting HTML errors to be raised as compile errors in VS and set your compatibility level/Doctype to XHTML 1.1 Strict to get them all. These settings are under Tools -> Options -> Text Editor -> HTML -> Validation
you could try with tidy
CSE HTML Validator is one I have used in the past.
It is not open source, but there is a free version.
来源：https://stackoverflow.com/questions/773070/are-there-any-standalone-html-markup-validation-tools