The Bloch sphere is the standard way to visualize a single qubit. Every point on the sphere's surface represents a valid quantum state. The north pole is |0⟩, the south pole is |1⟩, and the equator holds superposition states like |+⟩ and |−⟩.
Quantum gates act as rotations on this sphere. The X gate flips the qubit (180° around the x-axis), the Hadamard gate creates an equal superposition, and phase gates like S and T rotate around the z-axis. By composing rotations, any single-qubit state can be reached from any other.
This interactive tool lets you apply gates and watch the state vector move in real time. The trail shows the path of recent transformations, making it easier to build geometric intuition for how quantum gates work.