The shift to BYOD policies and web-first devices demands browser-based programming tools that balance accessibility and functionality. We introduce WebPython [name changed], a Python IDE combining novice- friendly features (Turtle graphics, robotics, error messages) with advanced capabilities (NumPy, Matplotlib). Its client-side execution and web worker architecture ensure non-blocking interactivity.

Our Python code is run in web assembly and performing only 3 times slower than native CPython but significantly faster than other web-based IDE to which we compared it. Deployed in classrooms with 750+ daily users, WebPython supports offline use, URL-based sharing of code, and aligns with existing curricula—demonstrating how web tools can rival local IDEs without compromising power or accessibility.