Accompanying Files
Observation Details

Certain images are not loaded on viewports below 1296px. Reproducible by setting browser viewport to ≤1295px and reloading the page. This behavior exists on multiple pages and as such is marked a global observation. The following example code is taken from the first missing image on page "IoT-Verteilerseite" in section "Die Kids Watch für die Sicherheit Ihres Kindes":

<div class="teaser__mainvisual teaser__mainvisual--left">
  <img
    class="lazy teaser__mainvisual-image"
    src="data:image/svg+xml;utf8,<svg xmlns=&quot;http://www.w3.org/2000/svg&quot; width=&quot;&quot; height=&quot;&quot; viewBox=&quot;0 0 1 1&quot;></svg>"
    data-src="https://www.telekom.de/resources/images/1226050/telekom-iot-doorpage-teaser-kidswatch-fruehling.webp"
    alt="Die Kids Watch für die Sicherheit Ihres Kindes"
    title="Die Kids Watch für die Sicherheit Ihres Kindes"
  >
  <noscript>
    <img
      class="teaser__mainvisual-image"
      src="https://www.telekom.de/resources/images/1226050/telekom-iot-doorpage-teaser-kidswatch-fruehling.webp"
      alt="Die Kids Watch für die Sicherheit Ihres Kindes"
      title="Die Kids Watch für die Sicherheit Ihres Kindes"
    />
  </noscript>
</div>

Observations about code markup:

  • Image's src attribute not used to provide image source

  • src attribute includes invalid character(s) (e.g. <)

  • title attribute used and duplicate of alt attribute

  • Unnecessary <noscript> used for image element that should not need javascript to be displayed

  • Image tag missing / before closing >

  • CSS class lazy used instead of image's built-in loading="lazy"

The reason for images not being loaded can be any combination of issues. See remediation notes for one recommendation to fix the issue by using clean, semantic HTML code.

Remediation Notes

Ensure all images are either loaded on page load or correctly lazy loaded later on.

  • Use the image's src attribute for the image source

  • Do not use title attribute on HTML image element

  • Ensure valid HTML code by running a validator tool like W3C NuHtml Validator

  • Keep code consistent (e.g. image with / without trailing / at the end of the tag)

Simplify above-mentioned example code:

<div class="teaser__mainvisual teaser__mainvisual--left">
  <img
    class="teaser__mainvisual-image"
    src="https://www.telekom.de/resources/images/1226050/telekom-iot-doorpage-teaser-kidswatch-fruehling.webp"
    alt="Die Kids Watch für die Sicherheit Ihres Kindes"
    loading="lazy"
  />
</div>