Live Python coding duels and DSA practice
CodeClash brings a competitive edge to solving data structures and algorithms problems. Play a live one-on-one coding duel, or work through an original question on your own. Python runs in your browser, so you can start without installing a local development environment.
How a coding duel works
- Sign in with Google or GitHub and choose your unique username.
- Join matchmaking. When an opponent is found, both players confirm they are ready.
- Receive the same Python problem and a shared 20-minute clock.
- Write your solution and run the public examples. In casual mode, the first reported successful completion ends the round.
- Review your result in match history and find another opponent.
Matchmaking needs another player to join. It does not guarantee an opponent or an immediate match.
Practice DSA without a timer
Solo practice lets you filter original CodeClash questions by topic and difficulty or choose a random problem. Run examples, try custom input, save drafts, and revisit your attempts. Reference explanations help you compare approaches after working on a problem.
The library contains 153 original questions covering arrays, strings, graphs, dynamic programming, and other foundations. It is not an official LeetCode or NeetCode question collection. Some questions are reserved for solo practice while their suitability for duels is reviewed.
What does browser execution mean?
Your Python code runs on your device through WebAssembly. The first run downloads the Python runtime; later runs can use cached files. Results and execution times depend on your device. A browser-reported pass is not a verified server verdict.
Does a duel change my rating?
No. The current casual beta does not change ratings. An authoritative judge and further fairness testing are needed before verified ranked play is enabled.
Is CodeClash free?
The current casual beta and solo practice are free to use. You need an account to enter the app and save progress.
Your profile and progress
Settings lets you edit your profile, select a theme, and sign out. Saved matches and practice attempts belong to your account. Read our privacy notice and fair-play guidance, or contact us with a question.