Kilotest: Violations of code invalid issue for Mozilla Foundation page

Basics

About the page

• URL: https://www.mozilla.org/en-US/
• Tested 32 days ago on 2026-09-08 at 04:02 by job 260908T0359-xmh
• Summary of results:
  • Rule engines:
    • Called: 12
    • Were able to test: 12
    • Reported any rule violations: 11
  • Violations: 753
  • Violators: 192
  • Issues: 47
• Download the full technical report (JSON)

About the issue

• Why it matters: Invalid code in the page may prevent a helper from working
• Priority: high
• Related WCAG standard: 4.1
• Reported by 1 rule engine (Html Checker API)
• Violations: 1
• Violators: 1

Violators

Here are the HTML elements reported to violate rules belonging to the code invalid issue.

Take me there links will open the page in a new tab and try to scroll to the element and highlight it. This does not always succeed. You can return here by closing the new tab.

• Element 626

  • 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: [not obtained]
  • Reported by Html Checker API
  • Take me there
  • What diagnoses were reported?