Charts

TwBoxPlotChart

TwBoxPlotChart is a Blazor box plot that summarises groups of raw values by median, quartiles, whiskers and outliers.

Last updated 18 October 2026

Please be aware this component is new, may have bugs and/or be subject to change. Please report any bugs at https://github.com/twblazor/twblazor/issues.

Basic usage

TwBoxPlotChart summarises each ChartSample of raw observations. The box spans the middle half of the values with a line at the median. Whiskers reach the furthest values within 1.5 times the length of the box, and anything beyond is drawn as an outlier dot.

Response times by serviceMilliseconds

RAZOR

<TwChart Title="Response times by service" Description="Milliseconds">
    <TwBoxPlotChart Samples="@_services" />
</TwChart>

CSHARP

@code {
    private readonly ChartSample[] _services =
    [
        new("Search", [112, 120, 131, 135, 138, 142, 144, 149, 151, 153, 290]),
        new("Checkout", [156, 158, 160, 163, 167, 170, 172, 176, 181, 185]),
        new("Reports", [190, 196, 204, 215, 228, 240, 262, 150, 310])
    ];
}

Horizontal

Set Horizontal to list the groups down the side, which suits long labels and many groups.

Response times by service

RAZOR

<TwChart Title="Response times by service">
    <TwBoxPlotChart Samples="@_services" Horizontal="true" Height="ChartHeight.Small" />
</TwChart>

Summary

Tooltips and the table view give the count, minimum, lower quartile, median, upper quartile and maximum of each group.

Shared features

The legend, tooltips, keyboard navigation, table view, value formatting, height and empty state work the same on every chart. See TwChart for those options.

The plot is a single Tab stop. Each data point is announced with its series and value as focus reaches it, and the table view presents the same data without the plot.

Key	What it does
`Tab`	Moves focus into the plot, onto the data point last visited.
`Arrow Right` or `Arrow Down`	Moves to the next data point.
`Arrow Left` or `Arrow Up`	Moves to the previous data point.
`Home` or `End`	Moves to the first or last data point.
`Escape`	Hides the tooltip of the focused data point.
`Enter` or `Space`	On a legend item: shows or hides that series. On the table button: switches between the chart and its data table.

TwBoxPlotChart

Basic usage

Horizontal

Summary

Shared features

Keyboard navigation