INPUT LAG VISUALIZER
Press SPACE or tap below. Watch the gap between your input and the response.
With lockstep, every frame waits for the opponent's input before advancing. You feel the full round-trip every time you press a button.
With rollback, the engine predicts the opponent locally and runs immediately. When the real input arrives and disagrees with the prediction, the engine quietly rewinds and replays. The round-trip is still on the wire — rollback hides it from you.
Real games add 1–3 frames of input buffer (~17–50 ms) regardless of mode — that's the small fixed delay that gives the network a head start. The contrast above isolates what the netcode itself adds on top: nothing for rollback, the full round-trip for lockstep. Mechanic, not opinion.