Secure context
This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The DPR header is a Client Hints headers which represents the client device pixel ratio (DPR), which is the the number of physical device pixels corresponding to every CSS pixel.

Header type Request header
Forbidden header name ?

Note: Client Hints are accessible only on secure origins (via TLS). Server has to opt in to receive DPR header from the client by sending Accept-CH and Accept-CH-Lifetime response headers.


DPR: <number>


Server first needs to opt in to receive DPR header by sending the response headers Accept-CH containing DPR and Accept-CH-Lifetime.

Accept-CH: DPR
Accept-CH-Lifetime: 86400

Then on subsequent requests the client might send DPR header back:

DPR: 1.0

Browser compatibility

ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Chrome Full support 46Edge Full support ≤79Firefox ? IE ? Opera Full support 33Safari ? WebView Android Full support 46Chrome Android Full support 46Firefox Android ? Opera Android Full support 33Safari iOS ? Samsung Internet Android Full support 5.0


Full support
Full support
Compatibility unknown
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.

See also