Chart.js/docs/charts/area.md

Area Chart

Both line and radar charts support a fill option on the dataset object which can be used to create space between two datasets or a dataset and a boundary, i.e. the scale origin, start, or end (see filling modes).

:::tip This feature is implemented by the filler plugin. :::

Filling modes

Mode	Type	Values
Absolute dataset index	number	1, 2, 3, ...
Relative dataset index	string	'-1', '-2', '+1', ...
Boundary	string	'start', 'end', 'origin'
Disabled 1	boolean	false
Stacked value below	string	'stack'
Axis value	object	{ value: number; }

¹ for backward compatibility, fill: true is equivalent to fill: 'origin'

Example

new Chart(ctx, {
    data: {
        datasets: [
            {fill: 'origin'},      // 0: fill to 'origin'
            {fill: '+2'},          // 1: fill to dataset 3
            {fill: 1},             // 2: fill to dataset 1
            {fill: false},         // 3: no fill
            {fill: '-2'},          // 4: fill to dataset 2
            {fill: {value: 25}}    // 5: fill to axis value 25
        ]
    }
});

If you need to support multiple colors when filling from one dataset to another, you may specify an object with the following option :

Param	Type	Description
target	number, string, boolean, object	The accepted values are the same as the filling mode values, so you may use absolute and relative dataset indexes and/or boundaries.
above	Color	If no color is set, the default color will be the background color of the chart.
below	Color	Same as the above.

Example with multiple colors

new Chart(ctx, {
    data: {
        datasets: [
            {
              fill: {
                target: 'origin',
                above: 'rgb(255, 0, 0)',   // Area will be red above the origin
                below: 'rgb(0, 0, 255)'    // And blue below the origin
              }
            }
        ]
    }
});

Configuration

Option	Type	Default	Description
plugins.filler.propagate	boolean	true	Fill propagation when target is hidden.

propagate

propagate takes a boolean value (default: true).

If true, the fill area will be recursively extended to the visible target defined by the fill value of hidden dataset targets:

Example using propagate

new Chart(ctx, {
    data: {
        datasets: [
            {fill: 'origin'},   // 0: fill to 'origin'
            {fill: '-1'},       // 1: fill to dataset 0
            {fill: 1},          // 2: fill to dataset 1
            {fill: false},      // 3: no fill
            {fill: '-2'}        // 4: fill to dataset 2
        ]
    },
    options: {
        plugins: {
            filler: {
                propagate: true
            }
        }
    }
});

propagate: true: -if dataset 2 is hidden, dataset 4 will fill to dataset 1 -if dataset 2 and 1 are hidden, dataset 4 will fill to 'origin'

propagate: false: -if dataset 2 and/or 4 are hidden, dataset 4 will not be filled