Live Python in your browser · Peer-to-peer · numpy, pandas, matplotlib
Create a room, write and run Python live. Participants see code and output in real time.
Direct connection: Participants' browsers connect directly to the instructor's browser (WebRTC). The browsers exchange their public IP addresses to establish this connection, so your IP address is disclosed to the other participants.
Connection setup (signaling, STUN & TURN): The nicohartmann.dev server is used to find the room and as a fallback for restrictive routers. With TURN, the encrypted data stream passes through the server as a relay only.
Python runs locally: Code runs exclusively in the instructor's browser (WebAssembly / Pyodide). Participants only see code and output; they cannot run or change anything.
Libraries: The editor (Monaco), Pyodide and the numpy/pandas/matplotlib packages are loaded from a CDN when needed, unless these files are hosted locally. Your IP address is transmitted to the CDN operator in the process.
What is stored? Nothing is stored permanently on the server. Nicknames, code and output exist only in the browsers' memory. As a safeguard, the instructor's code is saved in their own browser's local storage.