Tools

Note: These are only the ones that I recommend. Not all validation software is made equal.

[Progress: I am still compiling this list from my scribbles, bookmarks, post-it notes, and random note files. It is a work in progress. – Last updated on April 9, 2006.]

(X)HTML and XML Validators

• W3C Online HTML & XHTML Validator

  Checks (X)HTML, SVG, and MathML web documents for conformance to W3C Recommendations and other standards. This can be used for both online files, and uploaded offline files.

• WDG (X)HTML Online Validator

  Checks HTML and XHTML documents in the same way that the W3C validator does, but it includes an option to spider the entire site and check all your pages at once, as well as offering a batch mode which will check multiple urls.

• W3C Online XML Schema Validator

  Checks your XML schema for compliance with the most recent recommendations.

• STG Online XML Validator

  Checks your XML documents for compliance.

• W3C Online RDF/XML Validator

  Checks your RDF/XML documents against the most recent supported recommendations.

• Others

  You may see a list of others here at DMOZ and here at WDG.

CSS Validators

• W3C Online CSS Validator

  Checks CSS in (X)HTML documents or standalone for conformance to W3C recommendations.

RSS/ATOM Feed Validator

• W3C Online Feed Validator

Accessibility Compliance Checks

• Bobby – Watchfire WebXACT

  One of the best online accessibility compliance checks in existance. Can check 508 compliance, and all levels (A, AA, AAA) of the WCAG guidelines.

• Cynthia Says

  A favorite of mine for the same sort of quality checks you get from Bobby, with less interface clutter.

• WAVE

  Powered by the folks over at the marvelous WebAIM, this is a very good accessibility checker.

• TAW

  TAW (Web Accessibility Test – backwards) is another online check using the WCAG guidelines.

• HiSoftware

  Section 508 and WCAG 1.0 Check.

• Site Valet

  Section 508 and WCAG 1.0 Check.

• BITV

  Section 508 and WCAG 2.0 Check.