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 Device-Memory header is a Device Memory API header that works like Client Hints header which represents the approximate amount of RAM client device has.

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 Device-Memory header from the client by sending Accept-CH and Accept-CH-Lifetime response headers.


The amount of device RAM can be used as a fingerprinting variable, so values for the header are intentionally coarse to reduce the potential for its misuse. The header takes on the following values: 0.25, 0.5, 1, 2, 4, 8.

Device-Memory: <number>


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

Accept-CH: Device-Memory
Accept-CH-Lifetime: 86400

Then on subsequent requests the client might send Device-Memory header back:

Device-Memory: 1


Specification Status Comment
Device Memory 1
The definition of 'Device-Memory' in that specification.
Editor's Draft Initial definition.

Browser compatibility

ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Chrome Full support 61Edge Full support ≤79Firefox ? IE ? Opera Full support 48Safari ? WebView Android Full support 61Chrome Android Full support 61Firefox Android ? Opera Android ? Safari iOS ? Samsung Internet Android Full support 8.0


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