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

Kata In our dojo, ...

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 ...

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.

CodinGame is a challenge-based training platform for programmers where you can play with the hottest programming topics.

The programmer testing solution that matches your job descriptions and helps you hire great developers faster.

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

Topcoder gathers the world’s experts in design, development and data science to work on interesting and challenging problems. ...

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

Coderbyte is a place built for anyone to practice and perfect their programming skills. Challenges are added almost every day ...

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 ...