[Chartjs]-Chart.js compress vertical axis on barchart

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You can use logarithmic type yAxis

Default: linear

https://www.chartjs.org/docs/latest/axes/cartesian/logarithmic.html

var ctx = document.getElementById('myChart');

var myChart = new Chart(ctx, {
  type: 'bar',
  data: {
    labels: ["January", "February", "March", "April", "May", "June"],
    datasets: [{
      label: "Series 1",
      backgroundColor: "rgba(255,99,132,0.2)",
      borderColor: "rgba(255,99,132,1)",
      borderWidth: 2,
      hoverBackgroundColor: "rgba(255,99,132,0.4)",
      hoverBorderColor: "rgba(255,99,132,1)",
      data: [65, 59, 43, 81, 56, 950],
    }]
  },
  options: {
    scales: {
      yAxes: [{
        type: 'logarithmic',
        ticks: {
          callback: function(tick, index, ticks) {
            return tick.toLocaleString();
          }
        }
      }]
    }
  }
});
<script src="https://cdn.jsdelivr.net/npm/chart.js@2.8.0"></script>
<canvas id="myChart" width="400" height="200"></canvas>

Optimized ticks

50 * (Math.floor(i / 50)), // lower 50
50 * (Math.ceil(i / 50)) // higer 50

var ctx = document.getElementById('myChart');

var myChart = new Chart(ctx, {
  type: 'bar',
  data: {
    labels: ["January", "February", "March", "April", "May", "June"],
    datasets: [{
      label: "Series 1",
      backgroundColor: "rgba(255,99,132,0.2)",
      borderColor: "rgba(255,99,132,1)",
      borderWidth: 2,
      hoverBackgroundColor: "rgba(255,99,132,0.4)",
      hoverBorderColor: "rgba(255,99,132,1)",
      data: [65, 59, 43, 81, 56, 950],
    }]
  },
  options: {
    scales: {
      yAxes: [{
        type: 'logarithmic',
        ticks: {
          callback: function(tick, index, ticks) {
            return tick.toLocaleString();
          }
        },
        afterBuildTicks: function(pckBarChart) {
          pckBarChart.ticks = pckBarChart.chart.data.datasets[0].data.flatMap(i => [
            50 * (Math.floor(i / 50)), // lower 50
            50 * (Math.ceil(i / 50)) // higer 50
          ])
        }
      }]
    }
  }
});
<script src="https://cdn.jsdelivr.net/npm/chart.js@2.8.0"></script>
<canvas id="myChart" width="400" height="200"></canvas>

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