Highcharts has paddings and spacings that will make the area charts line appear inside of the chart element. To get full width line you need to disable some spacings and lines. You have to disable axis tiles and move the labels on the chart instead of outside. This works on all line type charts, but in this example I am using the area chart.
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var config = { chart: { type: 'area', spacingLeft: 0, spacingRight: 0, }, xAxis: { minPadding: 0, maxPadding: 0, }, yAxis: [ title: { text: null }, labels: { align: 'left', x: 3, y: 16 }, }, // Opposite side axis settings. { opposite: true, title: { text: null }, labels: { align: 'right', x: -3, y: 16, }, }], };Programming Language: Javascript