# HTML Checker upgraded to W3C Validator Nu 20.6

> Canonical HTML version: https://rocketvalidator.com/blog/html-validator-upgraded-to-w3c-validator-20-6
> Attribution: Rocket Validator (https://rocketvalidator.com)
> License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

The HTML validation server has been upgraded to the latest version released of Validator.nu by the W3C, which adds some fixes and improvements related with checking CSS, SVG, and ARIA.

<p>The HTML validation server on Rocket Validator has been upgraded to <a rel="nofollow" href="https://github.com/validator/validator/blob/master/CHANGELOG.md#20630">version 20.6.30 of Validator.nu</a> released by the W3C, which adds some fixes and improvements related with checking CSS, SVG, and ARIA:</p>
 
* CSS: Improvements in `calc()`, `min()/max()` checking.
* Allow `height` and `width` attributes for SVG symbol element.
* Allow `capture` attribute for the `input[type=file]` element.
* Allow `disabled` attribute for the `link[rel=stylesheet]` element.
* Treat custom elements as labelable elements for `label[for]` handling.
* ARIA: Fix bug that disallowed implicit combobox/listbox for select.
* ARIA: Improve error message for `alt`-less img with ARIA attributes.
* ARIA: Allow `section[role=doc-glossary]`.

## Time to re-check your sites!

<p>As usual, it's recommended to re-check your sites after the validation servers have been upgraded, to get the most up-to-date results. Remember that you can <a href="https://docs.rocketvalidator.com/scheduling/">schedule</a> your reports to run periodically, so you don't have to do that manually every time.</p>