TNC Sim is a free, open-source simulator for learning and exploring Heidenhain Klartext CNC programming. Write or import a program, inspect its toolpath, and watch the machining process in 3D directly in your browser. It supports common positioning commands, cycles, Q parameters, radius compensation, multiple tool shapes, and interactive lessons. The Android app also works fully offline. Early release—not a substitute for verification on a real machine.
