This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

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




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.


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


Specification Status Comment
ECMAScript Shared Memory and Atomics
The definition of 'SharedArrayBuffer.prototype.byteLength' in that specification.
Draft Initial definition.

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support No support No support 46 (46) [1] No support No support No support
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support No support 46.0 (46) [1] No support No support No support

[1] This feature is disabled by a preference setting. In about:config, set javascript.options.shared_memory to true

See also

Document Tags and Contributors

 Contributors to this page: fscholz
 Last updated by: fscholz,