Kilotest: Diagnoses of code invalid violation by HTML element 626 on Mozilla Foundation page

Here is how tools diagnose the code invalid issue for HTML element 626 of the Mozilla Foundation page.

Basics

• About the code invalid issue
  • Why it matters: Invalid code in the document may prevent a helper from working
  • Priority: high
  • Related WCAG standard: 4.1
• About the Mozilla Foundation page
  • URL: https://www.mozilla.org/en-US/
  • Tested on 2026-04-03 at 03:56
• About HTML element 626
  • Take me there
  • Tag name: HEADER
  • Text: Get Firefox news
  • Start tag: <header class="mzp-c-newsletter-header">
  • XPath: /html/body/div[2]/footer[1]/div[1]/div[1]/div[2]/form[1]/header[1]
  • Bounding box: x = 0, y = 0, width = 0, height = 0

Diagnoses

1. The element header must not appear as a descendant of the footer element.

   Tool: Html Checker API (World Wide Web Consortium)