faurusCheck on the sample first
Run your code on the sample, then submit for the hidden tests when you are ready.
Practice
25 skills. One judge. No toy answers.
1,800+ problems. Each skill is checked with its real tool: queries on real database servers, pages in a real browser, commands in a real shell, models with real Python libraries.
The 25 skills
Algorithms and programming
In C, C++, Java, Python, JavaScript and 6 more languages
Databases
On real database servers
Web development
Graded in a real browser and a real server
Systems and DevOps
In a real shell
Data and AI
NumPy, Pandas, scikit-learn, PyTorch and LLM apps
How it is judged
Every answer goes through the real judge.
The same path for a placement drill, a course lesson, a college test or a fest contest.
- 1
You write it
In the workspace, in your language. Run it on the sample as often as you like.
- 2
We compile it
On our judge, with the same compiler every time. A compile error is never counted as a try.
- 3
Hidden tests run
Edge cases, big inputs and time limits you cannot see, each in its own sandbox.
- 4
The verdict lands
Accepted, or exactly which kind of failure. It goes straight to your record and your report card.
While you practise
Run, get help, keep your record.
AI hints, editorials, discussions
A nudge without the answer, then see how others solved it. All switched off in contests and tests.
Insights, streaks, a profile
Personal insights on your dashboard, a streak to keep, and a public profile to show your work, or keep it private.