toHtml

DataFrame instances can be rendered to HTML. Rendering of hierarchical tables in HTML is supported by JS and CSS definitions that can be found in project resources.

Dataframes can also be formatted before being converted to HTML. See format for how to do this.

Depending on your environment, there can be different ways to use the result of toHtml functions.

IntelliJ IDEA

Working with the result

The following function produces HTML that includes JS and CSS definitions. It can be displayed in the browser and has parameters for customization.

df.toStandaloneHtml(DisplayConfiguration(rowsLimit = null)).openInBrowser()
df.toStandaloneHtml(DisplayConfiguration(rowsLimit = null)).writeHtml(File("/path/to/file"))
df.toStandaloneHtml(DisplayConfiguration(rowsLimit = null)).writeHtml(Path("/path/to/file"))

Composing multiple tables

toHtml and toStandaloneHtml return composable DataFrameHtmlData, which you can use to include additional scripts, elements, or styles at the end of the page or just to merge multiple tables into one HTML snippet.

val df1 = df.reorderColumnsByName()
val df2 = df.sortBy { age }
val df3 = df.sortByDesc { age }

listOf(df1, df2, df3).fold(DataFrameHtmlData.tableDefinitions()) { acc, df -> acc + df.toHtml() }

Jupyter Notebooks

Configuring display for individual output

toHtml is useful if you want to configure how a single cell is displayed. To configure the display for the entire notebook, please refer to the Jupyter Notebooks section.

df.toHtml(DisplayConfiguration(cellContentLimit = -1))

18 September 2025