Get really good at programming.

Develop fluency in 74 programming languages with our unique blend of learning, practice and mentoring. Exercism is fun, effective and 100% free, forever.

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Explore and get fluent in
74 programming languages

Python
Python
495,626 students
JavaScript
JavaScript
391,179 students
Java
Java
195,387 students
C++
C++
129,553 students
Go
Go
126,080 students
C#
C#
125,301 students
Rust
Rust
110,836 students
C
C
106,525 students
TypeScript
TypeScript
73,886 students
Bash
Bash
63,350 students
Ruby
Ruby
54,924 students
PHP
PHP
49,594 students
See all 74 Language Tracks

Over 6,918 coding exercises.
From "Allergies" to "Zebra Puzzle".

Learn by doing. Get better at programming through fun coding exercises that build your understanding of concepts.

Allergies

Allergies

Given a person's allergy score, determine whether or not they're allergic to a given item, and their full list of allergies.

C# Go Ruby
+40 more
Queen Attack

Queen Attack

Given the position of two queens on a chess board, indicate whether or not they are positioned so that they can attack each other

Java JavaScript TypeScript
+60 more
Zebra Puzzle

Zebra Puzzle

Which of the residents drinks water? Who owns the zebra? Can you solve the Zebra Puzzle with code?

Rust PHP C++
+70 more

Write code locally, in your own space

Exercism is primarily built as a CLI-first tool. Download and submit exercises right from your terminal.

Use the Exercism in-browser editor

Don't spend hours installing a language locally just to try it out. We support all 74 of our programming languages in our in-browser editor.

Get automated analysis on your code

Not quite sure how well you've done? We run automatic analysis on your solutions to give you quick feedback and points of improvement.

Deepen your knowledge with human mentoring, for free.

Discover new and exciting ways to approach an exercise by getting mentored on it. Become more familiar with the conventions, idioms and opinions of a particular programming language.

Why mentoring?

You don't know what you don't know

When learning a new language, the hardest part is not being aware of the gaps in your knowledge. Our mentors can look at your code and immediately see the ideas you're not familiar with and give you a level-up by unlocking new knowledge.

Learn language-specific conventions

Becoming fluent in a language is more than being able to write code in it - it's about being able to think in that language. Our mentors will help guide you to how to reshape your thinking to write idiomatic code.

Learning with others is fun

Getting feedback from real people is an amazingly exciting way to learn. And becoming a mentor and giving feedback yourself is an even bigger step forward. So complete the circle - be mentored and mentor 🎉