JavaScript Labs

Below you'll find a collection of my (more recent) JavaScript experiments. It's mostly educational progressive web apps, some Twitter bots and other creative stuff. I generally use these experiments to learn more about a certain technology or library, so don't take the code too seriously. 🐒

Feel free to drop me a line on Twitter if you like them.


A new year, a new JavaScript framework! Using svelte I created this PWA to help my kids with math. Goal was to create an app-like experience:

  • 💃 micro animations
  • ⛺ full offline support
  • ⌛ prefetching JavaScript
  • 💻 server side rendering
[2020] Play + Source

Lumber Jack

Weekend project to learn more about Mobx State Tree. Simple kids game inspired by Stardew Valley and Monty Python. Don't forget to turn on sound!

  • 🌳 mobx state tree
  • 💃 react pose for animations
  • 🚀 create-react-app + TypeScript
  • 🎺 web audio for sounds
[2019] Play + Source

Size of NPM

I thought it might be (mildly) interesting to keep track of how the NPM node_modules folder grows over time. This website keeps track of the size of the top 100 npm packages. It's been running for a while now and the results are... frightening?

[2018] View + Source

Protest Against

Feel like protesting against some minor injustice? This (somewhat silly) web app makes this as easy and fun as liking something on Facebook! Multiple users required, but you can also open more tabs (wait for the app to wake up).

[2018] Play + Source

Peter and the Wolf

Progressive Web App for kids, based upon the classical piece "Peter and the Wolf" by Prokofiev. Turns out that making large mp3s available offline is harder than I thought.

[2018] Play + Source

Finding Nora

I created this fun little PWA for my daughter Nora to help her spell her name. She loved it, hope you do too!

  • 🚀 create-react-app + TypeScript
  • ⛺ full offline support
  • 🎺 web audio for sounds
[2018] Play + Source

Star Wars
or Star Trek?

Why not both? Using just CSS and a little bit of JavaScript I recreated these classic science fiction intro's.

Star Trek + Source
Star Wars + Source

Rush hour timelapse

A Twitter bot that creates daily timelapse videos of the traffic jams in The Netherlands. No longer active, but you can still see some of the old timelapses.

[2016] @altijdfiles + Source

Term Search

A terminology search engine for translators. Currently only German-Dutch terms. Work in progress. [no longer active]

Technologies: NodeJS, Express, MongoDB, Loopback, ReactJS.

[2016] Source

Help Terence!

A Twitter bot raising emoji money for his trip around the world. Fun little experiment with social media and Twitter bots. [no longer active]

Technologies used: Express, MongoDB.

[2016] @helpTerence + Source

Word to Line Prices

A simple web app for translators that converts a price per word to a price per standard line (55 characters).

[2016] Visit the app + Source

Wikipedia edits by the Dutch government

Twitter bot inspired by @congressedits that monitors and Tweets any edits made to Wikipedia by the Dutch government.

[2014] @OverheidEdits + Source