The CSS Validation service is being maintained at W3C as an open source project, by W3C staff and volunteers, under the auspices of the Quality Assurance tools development effort "qa-dev".

It was first written by Philippe Le Hégaret and Sijtsche Smeman.

Thanks to...

Many people have contributed to this project at various stages of its life. Among them, the creators and maintainers wish to give particular thanks to:

Arnaud Le Hors, Daniel Dardailler, Colas Nahaboo, Philippe Kaplan, Michel Buffa, Jean-Philippe Orsini and Séverine Vouret, Stéphane Boyera and many more at INRIA (The French National Institute for Research in Computer Science and Control), Susan Lesch, Kjetil Kjernsmo, Susan Sims, Lars Marius Garshol, Anselm Baird-Smith, Yves Lafon, Benoit Mahé, Thierry Kormann; Håkon Wium Lie, Chris Lilley, Ian Jacobs and Vincent Mallet, Bert Bos, the initial supervisor on this project, Björn Höhrmann for his FAQ and bug reports, Jean-Guilhem Rouel for his many bug fixes, olivier Thereaux, Steph Troeth, Peter Zhelezniakov, Karl Dubost, Valerio Proietti and the MooTools team, Makoto Takahashi, and lastly, thanks to Tim Berners-Lee without whom none of this would have been possible.


The CSS validator is available in a number of languages, thanks to the work of the following benevolent translators:

If you wish to help with translations, see the process and list of pending translations on the W3C wiki site.