A free Python course
Short lessons, real Python in your browser, and feedback that tells you what to fix. It starts at the very beginning and works up to algorithms, classes and projects of your own.
Nothing to install No account needed to start Free
This is real Python. Press Run, then change a number and run it again.
How it works
Read a short explanation, guess what some code will do, write code yourself, then come back to it later so you don't forget it.
Short explanations, with examples you can run and change.
Guess what a piece of code will print before you run it. When you get it wrong, you find out exactly what you misunderstood.
Exercises are checked when you press Check. If something is wrong, it tells you what and on which line.
Questions from each lesson come back for review after a day, then three days, then a week, and so on.
The course
Each unit ends with a checkpoint that opens the next one. If you already know a topic, take its checkpoint straight away and skip ahead. All 40 units are open: 405 checked exercises, and about 55 hours of lessons at a steady pace. There are also challenges for reading and fixing code, and a playground that marks programs you write yourself.
Part 1
From your very first line to programs that make decisions, repeat themselves and are built from functions.
Part 2
Text, collections, files and errors: the everyday tools for programs that handle real information.
Part 3
Objects, recursion, algorithms and testing: how working programmers organise code that keeps growing.
Part 4
Decorators, data structures, dynamic programming and clean design, ending with a capstone and life beyond the browser.
Questions
No. Python runs inside your web browser, so all you need is a computer or tablet with Chrome, Edge, Firefox or Safari. The first lesson downloads Python once (about 12 MB) and your browser keeps it after that.
Yes. The first lesson assumes nothing at all, not even what a program is. Each idea is introduced on its own, practised, and used again in later lessons.
Not to start. Your progress is saved in this browser as you go. Create a free account whenever you like and it comes with you, so you can carry on from another device.
Lessons take 10 to 30 minutes, so you can do one in a lunch break, and a unit takes one to three hours. The times shown assume a steady pace. Allow 60 to 100 hours for the whole course, depending on how much extra practice you do.
Python 3.14, the current version. Everything you write here works the same on any computer with Python installed, and the final unit shows you how to set that up.
Exercises are checked by running your code against tests written for each one, so any working answer passes, not just one exact solution. In the playground, Review gives your own programs a mark out of 10 for style and common mistakes, and Tests lets you write your own checks. None of it uses AI: the same code always gets the same feedback.
No. Every unit ends with a checkpoint. Pass a checkpoint and the next unit opens, whether or not you did the lessons before it.