Welcome to the W3C Markup Validation Service; a free service that checks documents like HTML and XHTML for conformance to W3C Recommendations and other standards.

Validate Your Markup

Validate by URI

Enter the URI of the page you want to check. Advanced options are available from the Extended Interface.

Validate by File Upload

Select the file you want to upload and check. Advanced options are available from the Extended File Upload Interface.

Recent Updates

2004-05-07: Released version 0.6.5, a maintenance release easier to use and install, featuring new documentation, simpler navigation, new recovery mechanisms instead of fatal errors, and offering explanations in addition to error messages.
2002-12-01: Released version 0.6.1, a maintenance release to fix minor bugs.

These are the most recent major changes to this service. See "What's New" for more details.