Sec-CH-Device-Memory header

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

See full compatibility

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

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

The HTTP Sec-CH-Device-Memory request header is used in device client hints to indicate the approximate amount of available RAM on the client device, in gigabytes. The header is part of the Device Memory API.

Client hints are accessible only on secure origins. A server has to opt in to receive the Sec-CH-Device-Memory header from the client, by first sending the Accept-CH response header. Servers that opt in to the Sec-CH-Device-Memory client hint will typically also specify it in the Vary header to inform caches that the server may send different responses based on the header value in a request.

Header type	Request header, Client hint
Forbidden request header	No

Syntax

http

Sec-CH-Device-Memory: <number>

Directives

<number>

The approximate amount of device RAM.

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. Values are only reported in powers of two, and are clamped to an implementation-defined minimum lower value and a maximum upper value. These bounds may change over time (see browser compatibility table).

For example, if a browser does not report below 2 or above 32 then the value is one of: 2, 4, 8, 16, 32.

Examples

The server first needs to opt in to receive Sec-CH-Device-Memory header by sending the Accept-CH response header containing Sec-CH-Device-Memory:

http

Accept-CH: Sec-CH-Device-Memory

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

http

Sec-CH-Device-Memory: 1

Specifications

Specification
Device Memory API # iana-device-memory

Browser compatibility

	desktop					mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS
`Sec-CH-Device-Memory` request header Experimental	Chrome – Full support Chrome 61 (Release date: 2017-09-05) footnote , altname altname Alternate name: Device-Memory footnote Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8. footnote From Chrome 147, reported values are 2, 4, 8, 16, and 32. Chrome – Full support Chrome 97 (Release date: 2022-01-04) footnote footnote Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8. footnote From Chrome 147, reported values are 2, 4, 8, 16, and 32.	Edge – Full support Edge 79 (Release date: 2020-01-15) footnote , altname altname Alternate name: Device-Memory footnote Before Edge 147, reported values were 0.25, 0.5, 1, 2, 4, and 8. footnote From Edge 147, reported values are 2, 4, 8, 16, and 32. Edge – Full support Edge 97 (Release date: 2022-01-06) footnote footnote Before Edge 147, reported values were 0.25, 0.5, 1, 2, 4, and 8. footnote From Edge 147, reported values are 2, 4, 8, 16, and 32.	Firefox – No support Firefox footnote No support	Opera – Full support Opera 48 (Release date: 2017-09-27) footnote , altname altname Alternate name: Device-Memory footnote Before Opera 131, reported values were 0.25, 0.5, 1, 2, 4, and 8. footnote From Opera 131, reported values are 2, 4, 8, 16, and 32. Opera – Full support Opera 83 (Release date: 2022-01-19) footnote footnote Before Opera 131, reported values were 0.25, 0.5, 1, 2, 4, and 8. footnote From Opera 131, reported values are 2, 4, 8, 16, and 32.	Safari – No support Safari footnote No support	Chrome Android – Full support Chrome Android 61 (Release date: 2017-09-05) footnote , altname altname Alternate name: Device-Memory footnote From Chrome 147, reported values are 1, 2, 4, and 8. footnote Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8. Chrome Android – Full support Chrome Android 97 (Release date: 2022-01-04) footnote footnote From Chrome 147, reported values are 1, 2, 4, and 8. footnote Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.	Firefox for Android – No support Firefox for Android footnote No support	Opera Android – Full support Opera Android 45 (Release date: 2018-02-15) footnote , altname altname Alternate name: Device-Memory footnote From Chrome 147, reported values are 1, 2, 4, and 8. footnote Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8. Opera Android – Full support Opera Android 68 (Release date: 2022-03-30) footnote footnote From Chrome 147, reported values are 1, 2, 4, and 8. footnote Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.	Safari on iOS – No support Safari on iOS footnote No support	Samsung Internet – Full support Samsung Internet 8 (Release date: 2018-07-18) footnote , altname altname Alternate name: Device-Memory footnote From Chrome 147, reported values are 1, 2, 4, and 8. footnote Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8. Samsung Internet – Full support Samsung Internet 18 (Release date: 2022-08-08) footnote footnote From Chrome 147, reported values are 1, 2, 4, and 8. footnote Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.	WebView Android – Full support WebView Android 61 (Release date: 2017-09-05) footnote , altname altname Alternate name: Device-Memory footnote From Chrome 147, reported values are 1, 2, 4, and 8. footnote Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8. WebView Android – Full support WebView Android 97 (Release date: 2022-01-04) footnote footnote From Chrome 147, reported values are 1, 2, 4, and 8. footnote Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.	WebView on iOS – No support WebView on iOS footnote No support

Tip: you can click/tap on a cell for more information.

Full support: Full support
No support: No support
: Experimental. Expect behavior to change in the future.
: See implementation notes.
: Uses a non-standard name
: Has more compatibility info.

Sec-CH-Device-Memory header

Syntax

Directives

Examples

Specifications

Browser compatibility

Legend

See also