Achieve code mastery through challenge. Improve your skills by training with others on real code challenges

Kata In our dojo, ...

Built by CodeSignal , Code Arcade challenges players to solve programming tasks to complete game levels. It's a fun way to hon ...

A fun social platform for hackers to solve interesting puzzles, build quick hacks, code game bots and collaborate to solve rea ...

Project Euler is a series of challenging mathematical/computer programming problems that will require more than just mathemati ...

BitDegree is a blockchain powered education platform that aims to revolutionize education and the blockchain technology. The p ...

Develop your coding skills and practice them by competing with hundreds of players worldwide. Code your own bots in your prefe ...

Are you a code newbie? Learning to program is exhilarating and challenging... and also frustrating, exhausting, and overwhelmi ...

Learn to code (for free) with interactive challenges. Gain XP, unlock achievements and climb the leaderboard. It's the fastest ...

Halite is an artificial intelligence programming challenge.

LeetCode is a platform for learning and improving coding skills with the goal of being fully prepared for programming intervie ...

Screeps is a massive multiplayer online real-time strategy game. Each player can create his or her own colony in a single pers ...

This version of Ruby Warrior is a project by Bloc, a part-time online coding bootcamp for people who want to keep their curren ...

SPOJ (Sphere Online Judge) is an online judge system with over 315,000 registered users and over 20000 problems. The solution ...

CodeSignal is the leading provider of assessments for technical recruiting. As the creator of the Predictive Coding Score, Cod ...

CheckiO is expanding the world’s code literacy through gameplay. We always wanted to create the most entertaining game where g ...