Custom pie and doughnut chart labels

It’s easy to build a pie or doughnut chart in Chart.js. Follow the Chart.js documentation to create a basic chart config:

{
  type: 'pie',
  data: {
    labels: ['January', 'February', 'March', 'April', 'May'],
    datasets: [{
      data: [50, 60, 70, 180, 190]
    }]
  }
}

Let’s render it using QuickChart. Pack it into the URL:

https://quickchart.io/chart?c={type:'pie',data:{labels:['January','February', 'March','April', 'May'], datasets:[{data:[50,60,70,180,190]}]}}

This URL produces the following chart:

Note how QuickChart shows data labels, unlike vanilla Chart.js. This is because we automatically include the Chart.js datalabels plugin. To customize the color, size, and other aspects of data labels, view the datalabels documentation.

Here’s a simple example:

{
  type: 'pie',
  data: {
    labels: ['January', 'February', 'March', 'April', 'May'],
    datasets: [{
      data: [50, 60, 70, 180, 190]
    }]
  },
  options: {
    plugins: {
      datalabels: {
        display: true,
        align: 'bottom',
        backgroundColor: '#ccc',
        borderRadius: 3,
        font: {
          size: 18,
        }
      },
    }
  }
}

Note how we’re specifying the position of the data labels, as well as the background color, border, and font size:

The data labels plugin has a ton of options available for the positioning and styling of data labels. Check out the documentation to learn more.

The same approach works for doughnut charts as well. On top of that, we also include the Chart.js doughnutlabel plugin, which lets you put text in the center of your doughnut. You can combine this with Chart.js datalabel options for full customization.

Here’s a quick example that includes a center doughnut labels and custom data labels:

{
  type: 'doughnut',
  data: {
    labels: ['January', 'February', 'March', 'April', 'May'],
    datasets: [{
      data: [50, 60, 70, 180, 190]
    }]
  },
  options: {
    plugins: {
      datalabels: {
        display: true,
        backgroundColor: '#ccc',
        borderRadius: 3,
        font: {
          color: 'red',
          weight: 'bold',
        }
      },
      doughnutlabel: {
        labels: [{
          text: '550',
          font: {
            size: 20,
            weight: 'bold'
          }
        }, {
          text: 'total'
        }]
      }
    }
  }
}

That’s all for now. Try out your own Chart.js configs in the interactive sandbox and reach out if you have any questions!

About the author

Ian Webster is a software engineer and former Googler based in San Mateo, California. He has helped Google, NASA, and governments around the world improve their data pipelines and visualizations. In 2018, Ian created QuickChart, a collection of open-source APIs that support data visualization efforts.

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