W3C HTML Validation Service

Welcome to the W3C HTML Validation Service!

This is an easy-to-use HTML validation service based on an SGML parser. It checks HTML documents for compliance with W3C HTML Recommendations and other HTML standards.

Recent updates include:

• Updated XHTML 1.0, HTML 4.01 DTDs (January 26, 2000)
• Added support for HTML 4.01; updated XHTML 1.0 DTDs (August 24, 1999)
• Added username/password proxying (April 8, 1999)
• Added support for XHTML (March 4, 1999)
• Added support for Japanese character encodings (Feb 25, 1999)
• more...

You can also check your Cascading Style Sheets using W3C's CSS Validation Service.

Validate Documents by URI

Enter the location of a document you would like validated:

See Also

• Recent changes to this service
• The HTML authoring newsgroup (for help with HTML)
• How to provide feedback on this service
• DTDs (document types) supported by this service (the SGML catalog)
• Information on the source code availability
• The to-do list for the service
• The www-validator mailing list archives
• W3C's HTML home page
• The W3C HTML 4.0 Recommendation

Credits

This service uses:

• James Clark's excellent SGML parser,
• The libwww-perl library by Gisle Aas and Martijn Koster for retrieving documents.
• Neil Bowers' HTML style checker, Weblint.
• Patches and ideas from Terje Bless, Liam Quinn, and others.

The first online HTML validation service was created by Dan Connolly and Mark Gaither.

Gerald Oskoboiny
$Date: 2000-01-29 00:08:45 $