The Web Design Group

Validators and Checkers

Don't forget to check out the Web Design Group's own validators and checkers in our Tools section.

W3C MarkUp Validation Service
Online HTML and XHTML validator.
Online HTML, XHTML, and XML validator available in German, English, French, and Russian.
A Real Validator
Shareware HTML validator for Windows; offline version of the WDG HTML Validator.
Free HTML and XHTML validator for Linux and other Unix-like systems.
XML schema validator
Checks XHTML 1.0 documents against XML schemas, with detection of errors not found by other validators.
James Clark's multi-platform SGML parser that includes the SGML validator nsgmls.
Dave Raggett's free cross-platform utility for cleaning up HTML.
Shareware text and HTML editor for the Macintosh that includes an HTML validator.
STG XML Validation Form
Syntax validator for XML documents.
Web Page Backward Compatibility Viewer
Allows authors to view a page with selected tags unsupported--a good tool for ensuring cross-browser compatibility.
Web Page Purifier
Allows authors to view a page "purified" to be compliant with HTML 2.0, HTML 2.0+Tables, HTML 3.2, or webtv 1.1.
W3C CSS Validation Service
A free, easy-to-use CSS checker.
W3C Link Checker
A free, easy-to-use link checker.
HTML Validator for Firefox and Mozilla
Mozilla extension for checking pages in Firefox and Mozilla using Tidy or OpenSP.
Fee-based service that regularly checks a site's links and sends a report by e-mail.
Link tester and HTML lint that scans a site and sends a report by e-mail.
HTML PowerTools
Shareware Windows program that includes an offline link checker and a configurable quasi-validator.
CyberSpyder Link Test
Shareware Windows program to check the validity of hyperlinks.
Server-based link checker for UNIX and Windows NT.
Robots.txt Checker
Online checker for robots.txt syntax.
Web Link Validator
Shareware link checker for Windows. resources
A good collection of links to validators, accessibility checkers, and more.