Free build challenge
Build something real.
You’ve watched enough tutorials. Now build a small working app yourself, one step at a time: change the code, run it, and watch your app change.
Your project
Personal Expense Tracker
You’ll practise:
- Storing data
- Working with functions
- Handling input
- Calculating totals
- Debugging real code
Never coded? It’s beginner friendly: each step explains the one idea it needs, with hints if you get stuck. No signup, and your code stays on this device.
Common questions
About the build challenge
What will I build?
A personal expense tracker that runs in your browser: a list of things you spent money on, a total that adds them up, a form to add new expenses, a check that refuses bad amounts, and one feature you choose yourself. You write the data and the logic; the page draws the screen around them.
I have never coded. Can I do this?
Yes. It starts by changing one word and one number, and every step explains the one idea it needs. If you get stuck, there are two hints per step and then the solution. Nothing is timed or scored.
Which programming language does it use?
JavaScript, the language of the web: it runs in every browser, so there is nothing to install. The ideas you use (lists, loops, functions, checking input) work the same way in Python and most other languages.
Do I need to install anything or sign up?
No. It runs in your browser with nothing to install, no account and no email. Your progress is saved on your own device, so you can close the tab and carry on later.
Can I do it on my phone?
Yes. Each step asks you to write only a few lines, and there is a row of symbol keys for brackets and quotes. A laptop is more comfortable if you have one.
Is my code sent anywhere?
No. Your code runs in your own browser, in an isolated worker with no internet access, and it is only saved on your device. If you later book the free classes, only which steps you finished goes with the booking, never your code or the expenses you typed.