Kilotest: Diagnoses of box size absolute violation by HTML element 404 on Mozilla Foundation page

Basics

About the Mozilla Foundation page

• URL: https://www.mozilla.org/en-US/
• Tested 30 days ago by job 9wj on 2026-05-03 at 04:32

About HTML element 404

• Tag name: SOURCE
• Text: [not applicable]
• Start tag: <source media="(max-width: 1311px)" srcset="https://www.mozilla.org/media/img/home/2024/ai-gallery/collective-mobile-375.995e79a51592.jpg 375w,https://www.mozilla.org/media/img/home/2024/ai-gallery/collective-mobile-720.9922b34eb50a.jpg 720w,https://www.mozilla.org/media/img/home/2024/ai-gallery/collective-mobile-976.7d65d5663384.jpg 976w,https://www.mozilla.org/media/img/home/2024/ai-gallery/collective-mobile-1232.a39d1be9a023.jpg 1232w,https://www.mozilla.org/media/img/home/2024/ai-gallery/collective-mobile-1450.921cba2041a0.jpg 1450w" sizes="(min-width: 768px) calc((100vw - 32px) / 2),calc(100vw - 32px)" width="1450" height="723">
• XPath: /html/body/div[2]/main[1]/section[1]/div[1]/div[1]/div[1]/div[1]/picture[1]/source[1]
• Bounding box: x = 272, y = 2806, width = 0, height = 0

About the box size absolute issue

• Why it matters: User cannot enlarge the content of an item for readability
• Priority: high
• Related WCAG standard: 1.4.4

Diagnoses

Here is how tools diagnose the box size absolute issue for HTML element 404 of the Mozilla Foundation page.

1. [failed] The test target `width` attribute uses absolute units.

   Tool: QualWeb (University of Lisbon)

   Rule: QW-BP15