SharedArrayBuffer.prototype.byteLength

The byteLength accessor property represents the length of an SharedArrayBuffer in bytes.

Description

The byteLength property is an accessor property whose set accessor function is undefined, meaning that you can only read this property. The value is established when the shared array is constructed and cannot be changed.

Examples

Using byteLength

var sab = new SharedArrayBuffer(1024);
sab.byteLength; // 1024

Specifications

Specification
ECMAScript Language Specification (ECMAScript) # sec-get-sharedarraybuffer.prototype.bytelength

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
`byteLength`	68 60-63 Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of speculative side-channel attacks. This was a temporary removal while mitigations were put in place.	79 16-17 Support was removed to mitigate speculative execution side-channel attacks (Windows blog).	79 57 Support was disabled by default to mitigate speculative execution side-channel attacks (Mozilla Security Blog). 55-57 46-55	No	No	10.1-11	60-63 Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of speculative side-channel attacks. This is intended as a temporary measure until other mitigations are in place.	89 `SharedArrayBuffer` is gated behind COOP/COEP. For more detail, read Making your website "cross-origin isolated" using COOP and COEP. 60-63 Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of speculative side-channel attacks. This is intended as a temporary measure until other mitigations are in place.	79 57 Support was disabled by default to mitigate speculative execution side-channel attacks (Mozilla Security Blog). 55-57 46-55	No	10.3-11	15.0 `SharedArrayBuffer` is gated behind COOP/COEP. For more detail, read Making your website "cross-origin isolated" using COOP and COEP.