ArrayBuffer.prototype.maxByteLength

Baseline 2024
Newly available

Since July 2024, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The maxByteLength accessor property of ArrayBuffer instances returns the maximum length (in bytes) that this array buffer can be resized to.

Try it

const buffer = new ArrayBuffer(8, { maxByteLength: 16 });

console.log(buffer.byteLength);
// Expected output: 8

console.log(buffer.maxByteLength);
// Expected output: 16

Description

The maxByteLength 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, set via the maxByteLength option of the ArrayBuffer() constructor, and cannot be changed.

This property returns 0 if this ArrayBuffer has been detached. If this ArrayBuffer was constructed without specifying a maxByteLength value, this property returns a value equal to the value of the ArrayBuffer's byteLength.

Examples

Using maxByteLength

In this example, we create an 8-byte buffer that is resizable to a max length of 16 bytes, then return its maxByteLength:

js
const buffer = new ArrayBuffer(8, { maxByteLength: 16 });

buffer.maxByteLength; // 16

Specifications

Specification
ECMAScript® 2027 Language Specification
# sec-get-arraybuffer.prototype.maxbytelength

Browser compatibility

desktop mobile server
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Bun
Deno
Node.js
maxByteLength
Chrome – Full support
Chrome 111 (Release date: 2023-03-07)
footnote Full support
Edge – Full support
Edge 111 (Release date: 2023-03-13)
footnote Full support
Firefox – Full support
Firefox 128 (Release date: 2024-07-09)
footnote Full support
Opera – Full support
Opera 97 (Release date: 2023-03-22)
footnote Full support
Safari – Full support
Safari 16.4 (Release date: 2023-03-27)
footnote Full support
Chrome Android – Full support
Chrome Android 111 (Release date: 2023-03-07)
footnote Full support
Firefox for Android – Full support
Firefox for Android 128 (Release date: 2024-07-09)
footnote Full support
Opera Android – Full support
Opera Android 75 (Release date: 2023-05-17)
footnote Full support
Safari on iOS – Full support
Safari on iOS 16.4 (Release date: 2023-03-27)
footnote Full support
Samsung Internet – Full support
Samsung Internet 22 (Release date: 2023-07-14)
footnote Full support
WebView Android – Full support
WebView Android 111 (Release date: 2023-03-01)
footnote Full support
WebView on iOS – Full support
WebView on iOS 16.4 (Release date: 2023-03-27)
footnote Full support
Bun – Full support
Bun 1 (Release date: 2023-09-08)
footnote Full support
Deno – Full support
Deno 1.33 (Release date: 2023-04-28)
footnote Full support
Node.js – Full support
Node.js 20 (Release date: 2023-04-18)
footnote Full support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also