Code inside the browser in your chosen language, optimize your algorithms, and learn as you go.
Our in-browser code editor supports two modes of editor (in addition to normal): Emacs and VIM. Choose the one the works best for you. Don't worry, we won't judge.
We pre-fill the code editor with stubs for each language, so you can focus your time on coding the perfect solution. Use our defaults or code your own. "Customizable" is the key here.
Don't want to write your solution in the browser? No problem! You can easily code in your own environment and upload your solution for us to compile.
We currently support 22 programming languages and growing. Select your favorite or go for variety. We track your submissions by language so you can easily revise your solutions.
So you're rocking that brand new, 27" monitor and you want a code-environment to match? We've got that covered. Switch easily into full-screen and back again to match your needs.
Easily compile your code and test it against our testcases or testbot so you don't have to submit your code blindly. You can choose to use your own testcase, too. Troubleshooting in the browser....yup, that's pretty cool.
Our expanding set of challenges spans the full array of computer science disciplines. Whether you choose to solve them in order or by track, you’ll find hours of fun and thrilling excitement.