yAxis.minorUnit Number

The interval between minor divisions. It defaults to 1/5 of the yAxis.majorUnit. If the yAxis.type is set to "log", the minorUnit value represents the number of divisions between two major units and defaults to the major unit minus one.

Example - set the logarithmic y axis minor unit

<div id="chart"></div>
  yAxis: {
    type: "log",
    minorUnit: 2,
    minorGridLines: {
      visible: true
  series: [{
      type: "scatter",
      data: [[1, 3],[2, 20]]
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