# Welcome to the Highcharts Gantt JS (gantt) Options Reference

These pages outline the chart configuration options, and the methods and properties of Highcharts objects.

Feel free to search this API through the search bar or the navigation tree in the sidebar.

# chart.zooming.mouseWheel.type

Decides in what dimensions the user can zoom scrolling the wheel. Can be one of `x`, `y` or `xy`. In Highcharts Core, if not specified here, it will inherit the type from chart.zooming.type. In Highcharts Stock, it defaults to `x`.

Note that particularly with mouse wheel in the y direction, the zoom is affected by the default yAxis.startOnTick and endOnTick settings. In order to respect these settings, the zoom level will adjust after the user has stopped zooming. To prevent this, consider setting `startOnTick` and `endOnTick` to `false`.