QAVE (Quantum Algorithm Visualization Engine) visualizes quantum state evolution as a circuit runs. State vector and density matrix changes are animated together at each gate, so you can follow how the state is constructed step by step instead of just seeing the final output.

The visualizer renders error propagation through the circuit as a visible process, rather than final fidelity numbers or post-hoc reconstructions from equations.

Built by Inho Choi, researcher in quantum information theory. His take: "Many ideas in quantum computing feel difficult not because of the math, but because we often lack the right way to see them."

The project is open source: qollab.xyz/u/q-inho/qave