Valid HTML

What it checks

The home page's first 512 KB against the HTML standard, as the Nu Html Checker does.

Why it matters

Browsers repair invalid HTML, but not all the same way, and assistive technology and search engines may read it differently.

How to fix it

1. Fix the errors listed, starting with the first: a later error often follows from an earlier one.
2. Check the page again once they are fixed.