# 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.

# yAxis.gridLineWidth

The width of the grid lines extending the ticks across the plot area. Defaults to 1 on the Y axis and 0 on the X axis, except for 3d charts and gauges.

In gauges, the grid lines are limited to the pane's `size` and `innerSize`.

In styled mode, the stroke width is given in the `.highcharts-grid-line` class.