Kilotest: Diagnoses of attribute value invalid violation by HTML element 459 on Mozilla Foundation join us page

Basics

About the page

• URL: https://www.mozillafoundation.org/en/join-us/
• Tested 3 days ago on 2026-10-07 at 21:54 by job 261007T2132-l0b
• Summary of results:
  • Rule engines:
    • Called: 12
    • Were able to test: 12
    • Reported any rule violations: 11
  • Violations: 1762
  • Violators: 211
  • Issues: 46
• Download the full technical report (JSON)

About the issue

• Why it matters: Item behaves improperly
• Priority: highest
• Related WCAG standard: 1.3.1
• Reported by 1 rule engine (Html Checker)
• Violations: 12
• Violators: 6

About the violator

• Tag name: IMG
• Text: [not applicable]
• Start tag: <img src="https://assets.mofoprod.net/static/foundation_cms/_images/newsletter-signup-success.6d99125c1bf8.jpg" loading="lazy" width="100%" height="100%" alt="Newsletter signup success image">
• XPath: [not obtained]
• Bounding box: [not obtained]
• Reported by Html Checker

Diagnoses

Here is how rule engines diagnose the attribute value invalid issue for HTML element 459 of the Mozilla Foundation join us page.

1. Bad value 100% for attribute width on element img: Expected a digit but saw % instead.

   Rule engine: Html Checker (World Wide Web Consortium)

2. Bad value 100% for attribute height on element img: Expected a digit but saw % instead.

   Rule engine: Html Checker (World Wide Web Consortium)