[Solved]-Highcharts y axis thousands separator-Highcharts

If you find the above solution not working, try to add this:

Highcharts.setOptions({
  lang: {
    thousandsSep: ','
  }
});

In addition to what @jfrej suggested:

• If you're directly formatting an axis, use {value} for both yAxis and xAxis:
  • Fiddle for yAxis format
  • Fiddle for xAxis format
• If you're formatting a point in a tooltip, you may want to use {point.y} and/or {point.x}:
  • Fiddle for tooltip.pointFormat
  • Fiddle for tooltip.pointFormat with valueSuffix extension
• If you're directly formatting the point label, you may want to use {x} and/or {y}:
  • Fiddle for plotOptions.series.dataLabels, formatting all points
  • Fiddle for series.data.dataLabels, formatting specific point

So, since you're formatting yAxis, {value} should work as expected:

yAxis: {
    labels: {
        format: '{value:,.0f} €'
    }
}