About This HTML Issue
The device-width and device-height media features (including their min- and max- prefixed versions) were originally designed to query the physical dimensions of a device’s screen. In practice, this caused significant problems. On high-DPI (Retina) displays, max-device-width could report unexpected values depending on the device pixel ratio. When users resized their browser window, these features didn’t respond because the physical screen size never changed. And with browser zoom, the layout could break because the query still referenced the fixed device dimensions rather than the actual available space.
The Media Queries Level 4 specification formally deprecated these features. Modern browsers still support them for backward compatibility, but they should not be used in new code. The W3C validator raises this warning to encourage migration to the current standard.
The viewport-based equivalents — width, min-width, and max-width — respond to the browser’s layout viewport. This means they correctly adapt when the user resizes the window, zooms the page, or views the page in a split-screen mode. They also behave consistently across devices regardless of pixel density.
If your existing code uses max-device-width or min-device-width, the fix is straightforward: drop the word device from the feature name. For example, max-device-width: 768px becomes max-width: 768px. If you were relying on device dimensions to detect high-DPI screens, use the resolution media feature instead (e.g., min-resolution: 2dppx), which is the standards-compliant replacement for vendor-prefixed features like -webkit-min-device-pixel-ratio.
When choosing breakpoint values, prefer content-driven breakpoints — values where your layout actually needs to adapt — rather than targeting specific device widths. This produces more resilient designs that work well on any screen size.
Examples
Deprecated usage triggering the warning
The max-device-width media feature in the <style> block triggers the validator warning:
<!doctype html>
<html lang="en">
<head>
<title>Deprecated Media Feature</title>
<style>
/* Deprecated: queries the physical device screen */
@media only screen and (max-device-width: 480px) {
body {
background: pink;
}
}
</style>
</head>
<body>
<p>This page uses a deprecated media feature.</p>
</body>
</html>
The same warning appears if the deprecated feature is used in a <link> element’s media attribute:
<link rel="stylesheet" href="mobile.css" media="(max-device-width: 480px)">Fixed example using viewport-based queries
Replace max-device-width with max-width to query the viewport instead:
<!doctype html>
<html lang="en">
<head>
<title>Viewport-Based Media Query</title>
<style>
/* Correct: responds to the viewport width */
@media (max-width: 480px) {
body {
background: pink;
}
}
</style>
</head>
<body>
<p>This page uses a modern media feature.</p>
</body>
</html>
And for the <link> element:
<link rel="stylesheet" href="mobile.css" media="(max-width: 480px)">Replacing device pixel ratio queries
If you were using device-width features alongside -webkit-min-device-pixel-ratio to target high-DPI screens, switch to the standard resolution feature:
<style>
/* Deprecated approach */
@media (-webkit-min-device-pixel-ratio: 2) {
.logo {
background-image: url("logo@2x.png");
}
}
/* Standards-compliant replacement */
@media (min-resolution: 2dppx) {
.logo {
background-image: url("logo@2x.png");
}
}
</style>Quick reference of replacements
| Deprecated feature | Modern replacement |
|---|---|
max-device-width |
max-width |
min-device-width |
min-width |
max-device-height |
max-height |
min-device-height |
min-height |
-webkit-min-device-pixel-ratio: 2 |
min-resolution: 2dppx |
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