The “param” element is obsolete. Use the “data” attribute of the “object” element to set the URL of the external resource.

The <param> element is obsolete in HTML5 and should no longer be used inside <object> elements.

The <param> element was originally used to pass named parameters to plugins embedded via <object>, such as Flash, Java applets, or Windows Media Player. Since modern browsers have dropped support for these plugins, the <param> element lost its purpose and was removed from the HTML living standard.

If the <object> element references an external resource like a video, PDF, or image, the resource URL belongs in the data attribute of the <object> element itself. The type attribute should specify the MIME type of the resource.

For media playback, the <video> and <audio> elements are the standard replacements. For other embedded content, <iframe> or <embed> may be more appropriate depending on the use case.

HTML examples

Before: obsolete param element

<object>
  <param name="movie" value="video.mp4">
  <param name="autoplay" value="true">
</object>

After: using the data attribute on object

<object data="video.mp4" type="video/mp4">
  <p>Your browser does not support this content.</p>
</object>

After: using video for media playback

<video src="video.mp4" controls>
  <p>Your browser does not support this video.</p>
</video>

Learn more:

MDN Reference

HTML object element - MDN Web Docs

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MDN Reference

HTML param element (obsolete) - MDN Web Docs

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WHATWG Spec

Embedded content - WHATWG HTML Standard

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