CodinGame

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

Free Web

hackerrank.com

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

Free Web

Project Euler

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

Free Web

Spoj

Sphere Online Judge created for the coders' community to train, to learn and to make progress.

Free Web Self-Hosted

The AI Games

Develop your coding skills and practice them by competing with hundreds of players worldwide. Code your own bots in your preferred language and join the various...

Free Web

Code Arcade

built by codefights, code arcade challenges players to solve programming tasks to complete game levels. it's a fun way to hone...

Free Web

Hackerearth

a social and community platform for students and developers for solving programming puzzles, sharing notes and practicing concepts with the online editor, live...

Free Web