🎉 hey, I shipped skillcraft.ai
It's like Reddit, but for tech courses. Discover what developers actually recommend.
Up to date
Published
2 min read

Float16Array in JavaScript

Understanding the new 16-bit floating point array in JavaScript

Float16Array is a new type of array in JavaScript that stores 16-bit (2-byte) floating point numbers. It joins the existing family of TypedArrays like Int8Array, Uint8Array, Float32Array, and Float64Array

If you’ve never used TypedArrays before, think of them as specialized arrays that can only contain specific types of numbers.

Unlike regular JavaScript arrays that can mix strings, objects, and numbers, TypedArrays are fixed-size, memory-efficient arrays dedicated to numeric data.

Here’s how you’d create and use a Float16Array

JavaScript
// Create a Float16Array with 4 elements
const myArray = new Float16Array(4);
myArray[0] = 1.5;
myArray[1] = 42.0;
myArray[2] = 0.333;
myArray[3] = -27.5;
console.log(myArray); // Float16Array [1.5, 42, 0.3330078125, -27.5]

Notice something interesting with the third value? 0.333 became 0.3330078125. This happens because 16-bit floating point numbers have limited precision compared to JavaScript’s standard 64-bit numbers.

You might wonder: “We already have Float32Array and Float64Array, so why do we need a 16-bit version?”

The answer comes down to three things: memory, performance, and compatibility.

TypedArrayElement TypeBytes Per ElementDescriptionValue RangePrecision
Float16Array16-bit float216-bit IEEE floating point±65,504~3 decimal digits
Float32Array32-bit float432-bit IEEE floating point±3.4×10^38~7 decimal digits
Float64Array64-bit float864-bit IEEE floating point±1.8×10^308~15 decimal digits

A Float16Array uses half the memory of a Float32Array. If you’re working with large datasets, this can make a significant difference.

For applications processing millions of values, this memory saving can be crucial. In certain contexts, especially with GPU-accelerated computing, 16-bit floats can be processed more efficiently than 32-bit or 64-bit numbers. Newer GPUs often have specialized hardware for handling 16-bit floating point math, making operations potentially faster.

References


Found this article helpful? You might enjoy my free newsletter. I share dev tips and insights to help you grow your coding skills and advance your tech career.


Check out these related articles that might be useful for you. They cover similar topics and provide additional insights.

Javascript
7 min read

JavaScript Truthy and Falsy: A Deep Dive

Grasp JavaScript's type coercion with practical examples and avoid common pitfalls

Oct 27, 2024
Read article
Javascript
6 min read

setImmediate() vs setTimeout() in JavaScript

both setImmediate() and setTimeout() are used for scheduling tasks, but they work differently.

Sep 8, 2024
Read article
Javascript
3 min read

JavaScript's ??= Operator: Default Values Made Simple

A guide to using ??= in JavaScript to handle null and undefined values elegantly

Nov 5, 2024
Read article
Javascript
6 min read

Understanding JavaScript Closures With Examples

Closures are essential for creating functions that maintain state, without relying on global variables.

Sep 6, 2024
Read article
Javascript
9 min read

Exploring JavaScript Symbols

Deep dive into JavaScript Symbols - what they are, why they matter, and how to use them effectively

Nov 15, 2024
Read article
Javascript
3 min read

navigator.clipboard - The New Asynchronous Clipboard API in JavaScript

Copy and paste text, images, and files using the new navigator.clipboard API

Dec 7, 2024
Read article
Javascript
4 min read

Intl.DurationFormat: Format Time Durations with Locale Support

Stop writing manual duration formatting code. Instead, leverage the new powerful Intl.DateTimeFormat API for internationalized time displays

Mar 13, 2025
Read article
Javascript
4 min read

What is the JavaScript Pipeline Operator |>

A deep dive into how pipeline operators can make your code more readable and maintainable

Oct 29, 2024
Read article
Javascript
4 min read

Embrace Intermediate Variables and Early Returns in JavaScript

Early returns and intermediate variables make your code easier to reason about

Aug 30, 2024
Read article

This article was originally published on https://www.trevorlasn.com/blog/float16array-javascript. It was written by a human and polished using grammar tools for clarity.