Q: Highcharts gauge chart customization I need to display a white line in the middle of the gauge chart like this:

But I can't find a customization option suitable to do that in Highcharts gauge chart. Can anyone please help? 
I don't want the "gauge" arrow. I just want the white separator at 50%.

A: You can add the separator by using plotLines option:
yAxis: {
    plotLines: [{
        value: 100,
        width: 4,
        color: '#fff',
        zIndex: 4

    }],
    ...
}


Live demo: https://jsfiddle.net/BlackLabel/1mj80dc6/
API Reference: https://api.highcharts.com/highcharts/yAxis.plotLines
