Module source 

Attribute names for source (<source>) elements.

Purpose

The <source> element specifies multiple media resources for <picture>, <audio>, or <video> elements, enabling responsive images and fallback media formats.

Common Attributes

• src: Resource URL
• type: MIME type of the resource
• srcset: Responsive image sources (for <picture>)
• sizes: Image sizes for different viewports (for <picture>)
• media: Media query for when this source applies

Example

<video controls>
  <source src="video.webm" type="video/webm">
  <source src="video.mp4" type="video/mp4">
</video>
<picture>
  <source srcset="large.jpg" media="(min-width: 800px)">
  <source srcset="small.jpg" media="(max-width: 799px)">
  <img src="fallback.jpg" alt="Image">
</picture>

WHATWG Specification

• The source element

Constants

MEDIA

The media attribute.

SIZES

The sizes attribute.

SRC

The src attribute.

SRCSET

The srcset attribute.

TYPE

The type attribute.