History is enabled with chart: { history: { enabled: true } }. Every data update, zoom, pan, annotation and measurement commits a checkpoint. Right-click the plot to add a note, drop a dashed marker line, or start a measurement (context menu); drag-select or use the toolbar to zoom and pan; hold m and drag to measure; press Randomize to replace the data. Then step back with Undo / Redo (or press Cmd/Ctrl + Z and Shift + Cmd/Ctrl + Z). The buttons enable from the historyChange event via chart.history.state().