1KB JS Numbers Station

https://shkspr.mobi/blog/2025/07/1kb-js-numbers-station/

Code Golf is the art/science of creating wonderful little demos in an artificially constrained environment. This year the js1024 competition was looking for entries with the theme of "Creepy".

I am not a serious bit-twiddler. I can't create JS shaders which produce intricate 3D worlds in a scrap of code. But I can use slightly obscure JavaScript APIs!

There's something deliciously creepy about Numbers Stations - the weird radio frequencies which broadcast seemingly random numbers and words. Are they spies communicating? Commands for nuclear missiles? Long range radio propagation tests? Who knows!

So I decided to build one. Play with the demo.

Obviously, even the most extreme opus compression can't fit much audio into 1KB. Luckily, JavaScript has you covered! Most modern browsers have a built-in Text-To-Speech (TTS) API.

Here's the most basic example:

m = new SpeechSynthesisUtterance;m.text = "Hello";speechSynthesis.speak(m);

Run that JS and your computer will speak to you!

In order to make it creepy, I played about with the rate (how fast or slow it speaks) and the pitch (how high or low).

m.rate=Math.random();m.pitch=Math.random()*2;

It worked disturbingly well! High pitched drawls, rumbling gabbling, the languid cadence of a chattering friend. All rather creepy.

But what could I make it say? Getting it to read out numbers is pretty easy - this will generate a random integer:

s = Math.ceil( Math.random()*1000 );

But a list of words would be tricky. There's not much space in 1,024 bytes for anything complex. The rules say I can't use any external resources; so are there any internal sources of words? Yes!

Object.getOwnPropertyNames( globalThis );

That gets all the properties of the global object which are available to the browser! Depending on your browser, that's over 1,000 words!

But there's a slight problem. Many of them are quite "computery" words like "ReferenceError", "URIError", "Float16Array". I wanted all the single words - that is, anything which only has one capital letter and that's at the start.

const l = (n) => {    return ((n.match(/[A-Z]/g) || []).length === 1 && (n.charAt(0).match(/[A-Z]/g) || []).length === 1);};//   Get a random result from the filters = Object.getOwnPropertyNames( globalThis ).filter( l ).sort( ()=>.5-Math.random() )[0]

Rather pleasingly, that brings back creepy words like "Event", "Atomics", and "Geolocation".

Of course, Numbers Stations don't just broadcast in English. The TTS system can vocalise in multiple languages.

//   Set the language to Russianm.lang = "ru-RU";

OK, but where do we get all those language strings from? Again, they're built in and can be retrieved randomly.

var e = window.speechSynthesis.getVoices();m.lang = e[ (Math.random()*e.length) |0 ]

If you pass the TTS the number 555 and ask it to speak German, it will read out fünfhundertfünfundfünfzig.

And, if you tell the TTS to speak an English word like "Worker" in a foreign language, it will pronounce it with an accent.

Randomly altering the pitch, speed, and voice to read out numbers and dissociated words produces, I think, a rather creepy effect.

If you want to test it out, you can press this button. I find that it works best in browsers with a good TTS engine - let me know how it sounds on your machine.

🅝🅤🅜🅑🅔🅡🅢 🅢🅣🅐🅣🅘🅞🅝

With the remaining few bytes at my disposal, I produced a quick-and-dirty random pattern using Unicode drawing blocks. It isn't very sophisticated, but it does have a little random animation to it.

You can play with all the js1024 entries - I would be delighted if you voted for mine.