HTML Validation

Bad value “X” for attribute “media” on element “link”: unrecognized media “X”.

About This HTML Issue

The media attribute on a <link> element has not been recognized.

This attribute specified what media the linked resource is optimized for. As an example, the following will link a general stylesheet, and a specific one for printing:

<head>
  <link rel="stylesheet" type="text/css" href="general.css">
  <link rel="stylesheet" type="text/css" href="print.css" media="print">
</head>

Valid values for this attribute include:

all. Default, used for all media.
print. Used for printers and print previews.
screen. Used for computer, tablets or smartphone screens.

Learn more:

→ W3C: Media Type

Last reviewed: October 27, 2022

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Related W3C Validator Issues (83)

Bad value “X” for attribute “href” on element “link”: Illegal character in path segment: “X” is not allowed.

An illegal character has been found for the “href” attribute on the “link” element.

To fix this issue, find the “link” element in question and make sure that the “href” attribute contains a valid URL without any illegal characters.

Here’s some example HTML code of a link element:

<!DOCTYPE html>
<html>
  <head>
    <title>My Webpage</title>
    <link rel="stylesheet" href="styles/main.css">
  </head>
  <body>
    <h1>Welcome to my webpage!</h1>
    <p>Here is some content...</p>
  </body>
</html>

In the above example, the link element has a valid href attribute value of styles/main.css. Make sure that your href attribute values don’t contain any illegal characters.

Bad value “” for attribute “imagesizes” on element “link”: Must not be empty.

Bad value “” for attribute “imagesrcset” on element “link”: Must contain one or more image candidate strings.

Bad value X for attribute “media” on element “link”: Parse Error.

The media attribute on a <link> element specifies the media for which the linked resource is intended, using a valid media query. The value indicated is not a valid media query, which leads to a parse error.

Explanation

The media attribute is used to define what type of device the linked stylesheet should be applied to. Examples include common media types like screen, print, or all, as well as more complex media queries, such as (max-width: 600px) for responsive designs.

Correct Usage

Media Type Only:

You can specify general media types such as screen, print, or all.
```
<link rel="stylesheet" href="styles.css" media="screen">
```
Media Query:

For more precise control, use a media query to target specific conditions.
```
<link rel="stylesheet" href="styles.css" media="(max-width: 600px)">
```

Bad value X for attribute “media” on element “link”: The media “projection” has been deprecated

The media attribute on the link element cannot use the deprecated value projection; only valid CSS media types should be specified.

The media attribute specifies what media/device the linked resource is designed for, using a media query or a list of valid media types. In modern HTML and CSS, commonly accepted values include all, print, and screen.

The value projection was intended for projectors but has been deprecated and is no longer recognized by browsers or the HTML standard. To ensure validity and compatibility, remove projection and use only accepted types such as screen and/or print.

Incorrect example (with deprecated value):

<link rel="stylesheet" href="style.css" media="screen, projection">

Correct examples:

<link rel="stylesheet" href="style.css" media="screen">

<link rel="stylesheet" href="style.css" media="screen, print">

If you intend your stylesheet for screens and print, you can use both screen, print; for only screens, use just screen. If the stylesheet should apply to all devices, you can omit the media attribute or use all:

<link rel="stylesheet" href="style.css">

<link rel="stylesheet" href="style.css" media="all">

Bad value X for attribute “type” on element “link”: Expected a token character or “/” but saw “:” instead.

The value used to define the type of a link is not valid. You’re probably using a URL instead of a valid type.

Example of a valid type:

<link rel="icon" type="image/png" href="favicon.png">

A “link” element must have an “href” or “imagesrcset” attribute, or both.

A link element is invalid unless it contains at least one of the href or imagesrcset attributes.

The link element is used to define relationships between the current document and external resources, most commonly stylesheets. According to the HTML standard, a link must have either an href attribute, which points to the resource, or an imagesrcset attribute for responsive icons. If both are missing, the validator throws an error. This ensures that the link actually references a resource, otherwise it serves no functional purpose.

Correct usage:

With an href (for stylesheets, icons, etc.)

<link rel="stylesheet" href="styles.css">

With imagesrcset (for responsive icons)

<link rel="preload" as="image" type="image/png" imagesrcset="icon-1x.png 1x, icon-2x.png 2x">

A “link” element must not appear as a descendant of a “body” element unless the “link” element has an “itemprop” attribute or has a “rel” attribute whose value contains “dns-prefetch”, “modulepreload”, “pingback”, “preconnect”, “prefetch”, “preload”, “prerender”, or “stylesheet”.

link

A <link> element has been found in an invalid body context. Check the attributes of the <link> element and ensure it’s not within the <body> section.

If the element is within the <head> section, it may have been interpreted as a body context depending on previous elements. For example, while this <link> element is valid per se and is in the <head> section, it is deemed invalid because the previous <img> element made the validator consider it a body context:

<!DOCTYPE html>
<html lang="">
  <head>
    <title>Test</title>
    <img src="photo.jpg" alt="A smiling cat" />
    <link rel="canonical" href="https://example.com/" />
  </head>
  <body>
    <p>Some content</p>
  </body>
</html>

If we fix that document and move the <img> tag within the body, the issue raised about <meta> disappears because it’s now in a valid context:

<!DOCTYPE html>
<html lang="">
  <head>
    <title>Test</title>
    <link rel="canonical" href="https://example.com/" />
  </head>
  <body>
    <p>Some content</p>
    <img src="photo.jpg" alt="A smiling cat" />
  </body>
</html>

A “link” element with a “rel” attribute that contains the value “preload” must have an “as” attribute.

A “link” element with an “as” attribute must have a “rel” attribute that contains the value “preload” or the value “modulepreload”.

The error message indicates that the <link> element contains an as attribute, but its rel attribute does not hold the correct value. According to the HTML specification, when using the as attribute, the rel attribute must be set to "preload" or "modulepreload".

Explanation

The as attribute is used to specify the type of content being loaded, which helps the browser to handle it appropriately. To preload resources, you need to specify the rel attribute with the value "preload" (for general resources) or "modulepreload" (specifically for JavaScript modules).

Example with preload:

If you are preloading a stylesheet, the rel attribute should be set to "preload":

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Correct Usage of Link with as Attribute</title>
    <link rel="preload" href="styles.css" as="style">
</head>
<body>
    <p>Hello, World!</p>
</body>
</html>

Example with modulepreload:

If you are preloading a JavaScript module, the rel attribute should be set to "modulepreload":

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Correct Usage of Link with Modulepreload</title>
    <link rel="modulepreload" href="script.js" as="script">
</head>
<body>
    <p>Hello, World!</p>
</body>
</html>

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