Typed Arrays

Typed arrays and binary buffers are not available in SSJS. The SFMC server-side JavaScript engine (Jint) implements an ES3/ES5-era dialect and predates ES2015, so ArrayBuffer, DataView, all the integer/float TypedArray views, SharedArrayBuffer, and Atomics are entirely absent. Each is undefined, so referencing it yields undefined and constructing it (new Uint8Array()) fails because the constructor does not exist.

There is no way to work with raw binary data as a byte buffer in SSJS. When you need byte-level handling, either move the work into an external service reached over Platform.Function.HTTPRequest / the Script.Util.HttpRequest API, or use Platform.Function.Base64Encode / Base64Decode to move opaque binary payloads around as strings.

Status legend

Icon	Meaning
❌ Missing	Not available (`typeof` is `"undefined"`)

Members

Member	ES	Status	Notes
`ArrayBuffer`	ES6	❌ Missing	No raw byte buffer type
`SharedArrayBuffer`	ES2017	❌ Missing	No shared memory; engine is single-threaded
`DataView`	ES6	❌ Missing	No structured buffer access
`Atomics`	ES2017	❌ Missing	No shared-memory atomics
`Int8Array`	ES6	❌ Missing	See TypedArray views
`Uint8Array`	ES6	❌ Missing	See TypedArray views
`Uint8ClampedArray`	ES6	❌ Missing	See TypedArray views
`Int16Array`	ES6	❌ Missing	See TypedArray views
`Uint16Array`	ES6	❌ Missing	See TypedArray views
`Int32Array`	ES6	❌ Missing	See TypedArray views
`Uint32Array`	ES6	❌ Missing	See TypedArray views
`Float16Array`	ES2025	❌ Missing	See TypedArray views
`Float32Array`	ES6	❌ Missing	See TypedArray views
`Float64Array`	ES6	❌ Missing	See TypedArray views
`BigInt64Array`	ES2020	❌ Missing	See TypedArray views
`BigUint64Array`	ES2020	❌ Missing	See TypedArray views

ArrayBuffer

(ES6) — ❌ Missing. ArrayBuffer is not defined — typeof ArrayBuffer === "undefined". There is no fixed-length raw byte buffer in this engine. Use a regular Array of numbers if you only need an in-memory list, or Base64 strings for binary payloads.

SharedArrayBuffer

(ES2017) — ❌ Missing. SharedArrayBuffer is not defined — typeof SharedArrayBuffer === "undefined". The SSJS engine runs synchronously in a single thread, so there is no shared-memory concept to build on.

DataView

(ES6) — ❌ Missing. DataView is not defined — typeof DataView === "undefined". With no ArrayBuffer, there is nothing for a DataView to read or write.

Atomics

(ES2017) — ❌ Missing. Atomics is not defined — typeof Atomics === "undefined". Atomic operations only apply to shared memory, which does not exist here.

TypedArray views

All the concrete typed-array view constructors are not defined — each has typeof === "undefined":

Int8Array, Uint8Array, Uint8ClampedArray, Int16Array, Uint16Array, Int32Array, Uint32Array, Float16Array, Float32Array, Float64Array, BigInt64Array, BigUint64Array.

Because they depend on ArrayBuffer (also missing), there is no typed view over binary memory. Use a plain Array of JavaScript numbers when you need a numeric sequence:

// Instead of: var bytes = new Uint8Array(4);
var bytes = [0, 0, 0, 0];
bytes[0] = 255;
Write(bytes[0]); // 255 (no 0–255 clamping — you must enforce ranges yourself)

A plain array does not enforce element types or byte widths, and BigInt64Array / BigUint64Array additionally require BigInt, which is also unavailable.