The byteLength accessor property of ArrayBuffer instances returns the length (in bytes) of this array buffer.

Try it

// Create an ArrayBuffer with a size in bytes
const buffer = new ArrayBuffer(8);

// Use byteLength to check the size
const bytes = buffer.byteLength;

console.log(bytes);
// Expected output: 8

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 array is constructed and cannot be changed. This property returns 0 if this ArrayBuffer has been detached.

Examples

Using byteLength

const buffer = new ArrayBuffer(8);
buffer.byteLength; // 8

Specifications

Browser compatibility

See also

• ArrayBuffer