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Device Memory API

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

Note: This feature is available in Web Workers.

The capabilities of a client device largely depend on the amount of available RAM. Traditionally, developers had to use heuristics and either benchmark a device or infer device capabilities based on other factors like the device manufacturer or User Agent strings.

Determining device memory

There are two ways to determine the approximate amount of RAM a device has: use the Device Memory JavaScript API or accept Client Hints.

JavaScript API

You may query the approximate amount of RAM a device has by retrieving Navigator.deviceMemory or WorkerNavigator.deviceMemory.

const RAM = navigator.deviceMemory;

Client Hints

You may also use the Client Hints HTTP Header with the Device-Memory directive to retrieve the same approximate RAM capacity.

Interfaces

Extensions to other interfaces

Navigator.deviceMemory Read only: Returns the approximate amount of device memory in gigabytes.
WorkerNavigator.deviceMemory Read only: Returns the approximate amount of device memory in gigabytes.

Specifications

Specification
Device Memory>

Browser compatibility

api.Navigator.deviceMemory

	Desktop					Mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	WebView on iOS
`Device_Memory_API`	63	79	No	50	No	63	No	46	No	8.0	63	No

api.WorkerNavigator.deviceMemory

	Desktop					Mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	WebView on iOS
`Device_Memory_API`	65	79	No	52	No	65	No	47	No	9.0	65	No

http.headers.Device-Memory

	Desktop					Mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	WebView on iOS
`Device_Memory_API`	61	79	No	48	No	61	No	45	No	8.0	61	No