Web/JavaScript/Reference/Global objects/TypedArray/byteLength

The byteLength accessor property represents the length (in bytes) of a typed array.

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 a TypedArray is constructed and cannot be changed. If the TypedArray is not specifying an byteOffset or a length, the length of the referenced ArrayBuffer will be returned. TypedArray is one of the TypedArray objects.

Examples

Using the byteLength property

var buffer = new ArrayBuffer(8);

var uint8 = new Uint8Array(buffer);
uint8.byteLength; // 8 (matches the byteLength of the buffer)

var uint8 = new Uint8Array(buffer, 1, 5);
uint8.byteLength; // 5 (as specified when constructing the Uint8Array)

var uint8 = new Uint8Array(buffer, 2);
uint8.byteLength; // 6 (due to the offset of the constructed Uint8Array)

Specifications

Specification
[(ECMA-262)The definition of 'TypedArray.prototype.byteLength' in that specification.]

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`byteLength`	Chrome Full support 7	Edge Full support 14	Firefox Full support 4	IE Full support 10	Opera Full support 11.6	Safari Full support 5.1	WebView Android Full support 4	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 12	Safari iOS Full support 4.2	Samsung Internet Android Full support 1.0	nodejs Full support 0.10

Legend

Full support: Full support