W3C Markup Validation Service

The W3C's free service for checking the markup of HTML and XHTML documents.

FreeProprietaryWeb

These buttons open the developer's own site, repository or store listing in a new tab. wares.gg does not host downloads.

About W3C Markup Validation Service

The W3C Markup Validation Service checks web documents written in HTML, XHTML and related formats against their specifications. You can validate a page by URL, by uploading a file or by pasting markup directly.

Options let you set the character encoding, with a long list covering many languages, and the document type, or leave both to automatic detection. HTML5 support in this checker is marked experimental; the W3C's Nu Html Checker is a separate tool aimed at modern HTML.

Strengths

  • Validate by URL, file upload or direct input
  • Choice of character encoding and document type
  • Documented help for interpreting results

Limitations

  • HTML5 validation is marked experimental
  • Modern HTML is better served by the separate Nu Html Checker

Details

Pricing
FreeA free service run by the W3C.
License
Proprietary
Developer
W3C
Platforms
Web
How it runs
Web application
Account
Not required
Works offline
No
Best suited for
Checking HTML and XHTML documents against W3C specifications
Last verified
Added
Provenance
Selected from the TechWalrus Resource Hub (Website Checkers & Audit Tools); facts checked against the developer's own pages, 2 sources on file.

Report a wrong fact or a dead link on this listing