CodiqoLearn to code,
one bite at a time.
Free Python, JavaScript, C, C++, Java and C# courses with real code, instant feedback, streaks and leagues, and Pebble cheering you on.
Start learning freeI already have an accountNew to coding? Try your first lesson before you make an account.
Five minutes a day adds up
Learn in small steps
Each lesson explains one idea with worked examples, then asks you about it straight away. About five minutes each.
Write real code
Predict the output, fix the bug, fill the gap and build programs line by line. Every lesson ends with a short program you write yourself, and we run it for real.
Keep it going
Earn XP, open chests, climb weekly leagues and keep your streak alive, with Pebble the penguin cheering you on and Terry the mentor giving hints.
6 complete paths, 360 lessons
Python
60 lessons · 12 units · 4 chapters
Foundations → Logic and Repetition → Data and Functions → Applied Programming
See the Python course →JavaScript
60 lessons · 12 units · 4 chapters
Foundations → Logic and Repetition → Data and Functions → Applied JavaScript
See the JavaScript course →C
60 lessons · 12 units · 4 chapters
Foundations → Control Flow → Memory and Data → Building Programs
See the C course →C++
60 lessons · 12 units · 4 chapters
Foundations → Control Flow → Data Structures → Object-Oriented C++
See the C++ course →Java
60 lessons · 12 units · 4 chapters
Foundations → Control Flow → Data and Collections → Object-Oriented Java
See the Java course →C#
60 lessons · 12 units · 4 chapters
Foundations → Control Flow → Data and LINQ → Object-Oriented C#
See the C# course →Good to know
Is Codiqo free?
Yes. Every lesson, practice session, league and achievement is free. Free learners have Compile Fuel, which limits how many new lessons you can start in a row and refills over time. Codiqo Plus, an optional paid plan, will add unlimited Fuel and extra practice once payments are switched on.
What is Compile Fuel?
Starting a lesson uses 1 Fuel, and you can hold up to 3. Fuel refills by 1 every 8 hours, or you can fill it to the top in the shop for coins. Wrong answers never cost Fuel, resuming a lesson you already started is free, and practice sessions are always free.
Which language should I learn first?
If you've never coded before, we recommend Python: its syntax is short and readable. Choose JavaScript if you want to build websites, C if you want to understand how computers really work underneath, C++ for games and high-performance software, Java for Android and large business systems, or C# for Windows apps, web services and Unity games. You can learn as many as you like; each path has its own levels and progress.
Do you run my code?
Yes. Every lesson ends with a short program you write yourself, and we run it for real in a locked-down sandbox, then check it with tests, including some you can't see. Every example and expected output in the lessons was also produced by running the real code.
How much of the curriculum is available?
Every course you can choose is complete: 4 chapters, 12 units and 60 lessons each, ending in a capstone project and a final review. Every example and expected output was checked by running the real code, C, C++, Java and C# examples are compiled with warnings treated as errors, and C and C++ also run with undefined-behaviour checks.
Who are Pebble and Terry?
Pebble is your penguin companion who celebrates your progress and can be dressed up with items from the shop. Terry is your mentor: an experienced programmer who explains new ideas and gives you hints when you're stuck.