Code Treadmill

Like flash cards for code! Short programming challenges appear on a treadmill. The faster you solve them, the more points you earn!

What is it?

Problems are presented as pre-written “workouts” - curated sets of code problems in various languages and topics. During a workout, speed and accuracy are tracked as a revolutions-per-minute (RPM) score displayed on the sidebar.

Any workout can be turned into a multiplayer race. A race manager hosts the session and controls the pace. participants join by ID and compete on a live leaderboard.

Credits

Code Treadmill was originally designed and created by Brad Wray and is now maintained by Chris Jones. For some context and background about this project, see Chris's blog post here.

For a full list of other dependencies, see Dependencies.

Questions or ideas?

Open an issue or pull request on Codeberg.

For Students

How a workout session works — the exercise flow, available languages, and workout types.

How RPM, Complexity, and Score are calculated, including wrong answers and bonus problems.

Read, Write, Error, Parsons, Multiple Choice, and HTML/CSS live-preview exercises.

Topics, error types, write test formats, and special notes for each supported language.

Race Participant

How to join a race and compete in real time.

For Teachers

Hosting a multiplayer race — creating rooms, controlling the start, watching the leaderboard.

For Developers

Next.js, Docker, the dev.sh script, and Judge0 for sandboxed code execution.

Open-source libraries Code Treadmill builds on.

How to write new exercises and workouts, including the template placeholder reference.

The /admin interface for browsing exercises and assembling workouts.