Please see the package documentation site for how to use this package in LaTeX.

Overview

The goal of kableExtra is to help you build common complex tables and manipulate table styles. It imports the pipe %>% symbol from magrittr and verbalize all the functions, so basically you can add “layers” to a kable output in a way that is similar with ggplot2 and plotly.

To learn how to generate complex tables in LaTeX, please visit http://haozhu233.github.io/kableExtra/awesome_table_in_pdf.pdf

Installation

install.packages("kableExtra")

# For dev version
# install.packages("devtools")
devtools::install_github("haozhu233/kableExtra")

Getting Started

Here we are using the first few columns and rows from dataset mtcars

library(knitr)
## Warning: package 'knitr' was built under R version 3.4.1
library(kableExtra)
dt <- mtcars[1:5, 1:6]

When you are using kable(), if you don’t specify format, by default it will generate a markdown table and let pandoc handle the conversion from markdown to HTML/PDF. This is the most favorable approach to render most simple tables as it is format independent. If you switch from HTML to pdf, you basically don’t need to change anything in your code. However, markdown doesn’t support complex table. For example, if you want to have a double-row header table, markdown just cannot provide you the functionality you need. As a result, when you have such a need, you should define format in kable() as either “html” or “latex”. You can also define a global option at the beginning using options(knitr.table.format = "html") so you don’t repeat the step everytime. In this tutorial, I’ll still put format="html" in the function in case users just want to quickly replicate the results.

options(knitr.table.format = "html") 
## If you don't define format here, you'll need put `format = "html"` in every kable function.

Basic HTML table

Basic HTML output of kable looks very crude. To the end, it’s just a plain HTML table without any love from css.

kable(dt, "html")
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Bootstrap theme

When used on a HTML table, kable_styling() will automatically apply twitter bootstrap theme to the table. Now it should looks the same as the original pandoc output (the one when you don’t specify format in kable()) but this time, you are controlling it.

dt %>%
  kable("html") %>%
  kable_styling()
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Table Styles

kable_styling offers a few other ways to customize the look of a HTML table.

Bootstrap table classes

If you are familiar with twitter bootstrap, you probably have already known its predefined classes, including striped, bordered, hover, condensed and responsive. If you are not familiar, no worries, you can take a look at their documentation site to get a sense of how they look like. All of these options are available here.

For example, to add striped lines (alternative row colors) to your table and you want to highlight the hovered row, you can simply type:

kable(dt, "html") %>%
  kable_styling(bootstrap_options = c("striped", "hover"))
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

The option condensed can also be handy in many cases when you don’t want your table to be too large. It has slightly shorter row height.

kable(dt, "html") %>%
  kable_styling(bootstrap_options = c("striped", "hover", "condensed"))
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Tables with option responsive looks the same with others on a large screen. However, on a small screen like phone, they are horizontally scrollable. Please resize your window to see the result.

kable(dt, "html") %>%
  kable_styling(bootstrap_options = c("striped", "hover", "condensed", "responsive"))
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Full width?

By default, a bootstrap table takes 100% of the width. It is supposed to use together with its grid system to scale the table properly. However, when you are writing a rmarkdown document, you probably don’t want to write your own css/or grid. For some small tables with only few columns, a page wide table looks awful. To make it easier, you can specify whether you want the table to have full_width or not in kable_styling. By default, full_width is set to be TRUE for HTML tables (note that for LaTeX, the default is FALSE since I don’t want to change the “common” looks unless you specified it.)

kable(dt, "html") %>%
  kable_styling(bootstrap_options = "striped", full_width = F)
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Position

Table Position only matters when the table doesn’t have full_width. You can choose to align the table to center, left or right side of the page

kable(dt, "html") %>%
  kable_styling(bootstrap_options = "striped", full_width = F, position = "left")
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Becides these three common options, you can also wrap text around the table using the float-left or float-right options.

kable(dt, "html") %>%
  kable_styling(bootstrap_options = "striped", full_width = F, position = "float_right")
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras sit amet mauris in ex ultricies elementum vel rutrum dolor. Phasellus tempor convallis dui, in hendrerit mauris placerat scelerisque. Maecenas a accumsan enim, a maximus velit. Pellentesque in risus eget est faucibus convallis nec at nulla. Phasellus nec lacinia justo. Morbi fermentum, orci id varius accumsan, nibh neque porttitor ipsum, consectetur luctus risus arcu ac ex. Aenean a luctus augue. Suspendisse et auctor nisl. Suspendisse cursus ultrices quam non vulputate. Phasellus et pharetra neque, vel feugiat erat. Sed feugiat elit at mauris commodo consequat. Sed congue lectus id mattis hendrerit. Mauris turpis nisl, congue eget velit sed, imperdiet convallis magna. Nam accumsan urna risus, non feugiat odio vehicula eget.

Font size

If one of your tables is huge and you want to use a smaller font size for that specific table, you can use the font_size option.

kable(dt, "html") %>%
  kable_styling(bootstrap_options = "striped", font_size = 7)
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Column / Row Specification

Column spec

When you have a table with lots of explanatory texts, you may want to specified the column width for different column, since the auto adjust in HTML may not work in its best way while basic LaTeX table is really bad at handling text wrapping. Also, sometimes, you may want to highlight a column (e.g. a “Total” column) by making it bold. In these scenario, you can use column_spec(). You can find an example below.

Warning: If you have a super long table, you should be cautious when you use column_spec as the xml node modification takes time.

text_tbl <- data.frame(
  Items = c("Item 1", "Item 2", "Item 3"),
  Features = c(
    "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin vehicula tempor ex. Morbi malesuada sagittis turpis, at venenatis nisl luctus a. ",
    "In eu urna at magna luctus rhoncus quis in nisl. Fusce in velit varius, posuere risus et, cursus augue. Duis eleifend aliquam ante, a aliquet ex tincidunt in. ", 
    "Vivamus venenatis egestas eros ut tempus. Vivamus id est nisi. Aliquam molestie erat et sollicitudin venenatis. In ac lacus at velit scelerisque mattis. "
  )
)

kable(text_tbl, "html") %>%
  kable_styling(full_width = F) %>%
  column_spec(1, bold = T, border_right = T) %>%
  column_spec(2, width = "30em", background = "yellow")
Items Features
Item 1 Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin vehicula tempor ex. Morbi malesuada sagittis turpis, at venenatis nisl luctus a.
Item 2 In eu urna at magna luctus rhoncus quis in nisl. Fusce in velit varius, posuere risus et, cursus augue. Duis eleifend aliquam ante, a aliquet ex tincidunt in.
Item 3 Vivamus venenatis egestas eros ut tempus. Vivamus id est nisi. Aliquam molestie erat et sollicitudin venenatis. In ac lacus at velit scelerisque mattis.

Row spec

Similar with column_spec, you can define specifications for rows. Currently, you can either bold or italiciz an entire row. Note that, similar with other row-related functions in kableExtra, for the position of the target row, you don’t need to count in header rows or the group labelling rows.

kable(dt, "html") %>%
  kable_styling("striped", full_width = F) %>%
  column_spec(5:7, bold = T) %>%
  row_spec(3:5, bold = T, color = "white", background = "#D7261E")
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Header Rows

One special case of row_spec is that you can specify the format of the header row via row_spec(row = 0, ...).

kable(dt, format = "html") %>%
  kable_styling("striped", full_width = F) %>%
  row_spec(0, angle = -45)
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Cell/Text Specification

Function cell_spec is introduced in version 0.6.0 of kableExtra. Unlike column_spec and row_spec, this function is designed to be used before the data.frame gets into the kable function. Comparing with figuring out a list of 2 dimentional index for targeted cells, this design is way easier to learn and use and it fits perfectly well with dplyr’s mutate and summarize functions. With this design, there are two things to be noted: * Since cell_spec generates raw HTML or LaTeX code, make sure you remember to put escape = FALSE in kable. At the same time, you have to escape special symbols including % manually by yourself * cell_spec needs a way to know whether you want html or latex. You can specify it locally in function or globally via the options(knitr.table.format = "latex") method as suggested at the beginning. If you don’t provide anything, this function will output as HTML by default.

Currently, cell_spec supports features including bold, italic, monospace, text color, background color, align, font size & rotation angle. More features may be added in the future. Please see function documentations as reference.

Conditional logic

It is very easy to use cell_spec with conditional logic. Here is an example.

library(dplyr)
mtcars[1:10, 1:2] %>%
  mutate(
    car = row.names(.),
    # You don't need format = "html" if you have ever defined options(knitr.table.format)
    mpg = cell_spec(mpg, "html", color = ifelse(mpg > 20, "red", "blue")),
    cyl = cell_spec(cyl, "html", color = "white", align = "c", angle = 45, 
                    background = factor(cyl, c(4, 6, 8), 
                                        c("#666666", "#999999", "#BBBBBB")))
  ) %>%
  select(car, mpg, cyl) %>%
  kable("html", escape = F) %>%
  kable_styling("striped", full_width = F)
car mpg cyl
Mazda RX4 21 6
Mazda RX4 Wag 21 6
Datsun 710 22.8 4
Hornet 4 Drive 21.4 6
Hornet Sportabout 18.7 8
Valiant 18.1 6
Duster 360 14.3 8
Merc 240D 24.4 4
Merc 230 22.8 4
Merc 280 19.2 6

Visualize data with Viridis Color

This package also comes with a few helper functions, including spec_color, spec_font_size & spec_angle. These functions can rescale continuous variables to certain scales. For example, function spec_color would map a continuous variable to any viridis color palettes. It offers a very visually impactful representation in a tabular format.

iris[1:10, ] %>%
  mutate_if(is.numeric, function(x) {
    cell_spec(x, "html", bold = T, color = spec_color(x, end = 0.9),
              font_size = spec_font_size(x))
  }) %>%
  mutate(Species = cell_spec(
    Species, "html", color = "white", bold = T,
    background = spec_color(1:10, end = 0.9, option = "A", direction = -1)
  )) %>%
  kable("html", escape = F, align = "c") %>%
  kable_styling("striped", full_width = F)
Sepal.Length Sepal.Width Petal.Length Petal.Width Species
5.1 3.5 1.4 0.2 setosa
4.9 3 1.4 0.2 setosa
4.7 3.2 1.3 0.2 setosa
4.6 3.1 1.5 0.2 setosa
5 3.6 1.4 0.2 setosa
5.4 3.9 1.7 0.4 setosa
4.6 3.4 1.4 0.3 setosa
5 3.4 1.5 0.2 setosa
4.4 2.9 1.4 0.2 setosa
4.9 3.1 1.5 0.1 setosa

In the example above, I’m using the mutate functions from dplyr. You don’t have to use it. Base R solutions like iris$Species <- cell_spec(iris$Species, color = "red") also works.

Text Specification

If you check the results of cell_spec, you will find that this function does nothing more than wrapping the text with appropriate HTML/LaTeX formatting syntax. The result of this function is just a vector of character strings. As a result, when you are writing a rmarkdown document or write some text in shiny apps, if you need extra markups other than bold or italic, you may use this function to color, change font size or rotate your text.

An aliased function text_spec is also provided for a more literal writing experience. In HTML, there is no difference between these two functions.

sometext <- strsplit(paste0(
  "You can even try do do some crazy things like this paragraph. ", 
  "It seems to be a useless feature at this moment but who cares. ", 
  "It is so fun to play with color that I can't stop. ;D"
), " ")[[1]]
text_formatted <- paste(
  text_spec(sometext, "html", color = spec_color(1:length(sometext), end = 0.9),
            font_size = spec_font_size(1:length(sometext), begin = 5, end = 20)),
  collapse = " ")

# To display the text, type `r text_formatted` outside of the chunk

You can even try do do some crazy things like this paragraph. It seems to be a useless feature at this moment but who cares. It is so fun to play with color that I can’t stop. ;D

Tooltip

It’s very easy to add a tooltip to text via cell_spec. For example, text_spec("tooltip", color = "red", tooltip = "Hello World") will give you something like Hover over me (you need to wait for a few seconds before your browser renders it).

Note that the original browser-based tooltip is slow. If you want to have a faster response, you may want to initialize bootstrap’s tooltip by putting the following HTML code on the page.

<script>
$(document).ready(function(){
    $('[data-toggle="tooltip"]').tooltip(); 
});
</script>

In a rmarkdown document, you can just drop it outside of any R chunks. Unfortunately however, for rmarkdown pages with a floating TOC (like this page), you can’t use bootstrap tooltips because there is a conflict in namespace between Bootstrap and JQueryUI (tocify.js). As a result, I can’t provide a live demo here. If you want to have a tooltip together with a floating TOC, you should use popover which has a very similar effect.

Popover Message

The popover message looks very similar with tooltip but it can hold more contents. Unlike tooltip which can minimally work without you manually enable that module, you have to enable the popover module to get it work. The upper side is that there is no conflict between Bootstrap & JQueryUI this time, you can use it without any concern.

<script>
$(document).ready(function(){
    $('[data-toggle="popover"]').popover(); 
});
</script>
popover_dt <- data.frame(
  position = c("top", "bottom", "right", "left"),
  stringsAsFactors = FALSE
)
popover_dt$`Hover over these items` <- cell_spec(
  paste("Message on", popover_dt$position), # Cell texts
  popover = spec_popover(
    content = popover_dt$position,
    title = NULL,                           # title will add a Title Panel on top
    position = popover_dt$position
  ))
kable(popover_dt, "html", escape = FALSE) %>%
  kable_styling("striped", full_width = FALSE)
position Hover over these items
top Message on top
bottom Message on bottom
right Message on right
left Message on left

Grouped Columns / Rows

Add header rows to group columns

Tables with multi-row headers can be very useful to demonstrate grouped data. To do that, you can pipe your kable object into add_header_above(). The header variable is supposed to be a named character with the names as new column names and values as column span. For your convenience, if column span equals to 1, you can ignore the =1 part so the function below can be written as `add_header_above(c(" “,”Group 1" = 2, “Group 2” = 2, “Group 3” = 2)).

kable(dt, "html") %>%
  kable_styling("striped") %>%
  add_header_above(c(" " = 1, "Group 1" = 2, "Group 2" = 2, "Group 3" = 2))
Group 1
Group 2
Group 3
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

In fact, if you want to add another row of header on top, please feel free to do so.

kable(dt, "html") %>%
  kable_styling(c("striped", "bordered")) %>%
  add_header_above(c(" ", "Group 1" = 2, "Group 2" = 2, "Group 3" = 2)) %>%
  add_header_above(c(" ", "Group 4" = 4, "Group 5" = 2)) %>%
  add_header_above(c(" ", "Group 6" = 6))
Group 6
Group 4
Group 5
Group 1
Group 2
Group 3
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Group rows via labeling

Sometimes we want a few rows of the table being grouped together. They might be items under the same topic (e.g., animals in one species) or just different data groups for a categorical variable (e.g., age < 40, age > 40). With the new function group_rows() in kableExtra, this kind of task can be completed in one line. Please see the example below. Note that when you count for the start/end rows of the group, you don’t need to count for the header rows nor other group label rows. You only need to think about the row numbers in the “original R dataframe”.

kable(mtcars[1:10, 1:6], "html", caption = "Group Rows") %>%
  kable_styling("striped", full_width = F) %>%
  group_rows("Group 1", 4, 7) %>%
  group_rows("Group 2", 8, 10)
Group Rows
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160.0 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875
Datsun 710 22.8 4 108.0 93 3.85 2.320
Group 1
Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215
Hornet Sportabout 18.7 8 360.0 175 3.15 3.440
Valiant 18.1 6 225.0 105 2.76 3.460
Duster 360 14.3 8 360.0 245 3.21 3.570
Group 2
Merc 240D 24.4 4 146.7 62 3.69 3.190
Merc 230 22.8 4 140.8 95 3.92 3.150
Merc 280 19.2 6 167.6 123 3.92 3.440

Another way to use group_rows is to provide an grouping index, similar with add_header_above(). This feature is only available in kableExtra > 0.5.2.

# Not evaluated. This example generates the same table as above.
kable(mtcars[1:10, 1:6], "html", caption = "Group Rows") %>%
  kable_styling("striped", full_width = F) %>%
  group_rows(index = c(" " = 3, "Group 1" = 4, "Group 2" = 3))

For advanced users, you can even define your own css for the group labeling.

kable(dt, "html") %>%
  kable_styling("striped", full_width = F) %>%
  group_rows("Group 1", 3, 5, label_row_css = "background-color: #666; color: #fff;")
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Group 1
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Row indentation

Unlike group_rows(), which will insert a labeling row, sometimes we want to list a few sub groups under a total one. In that case, add_indent() is probably more apporiate. For advanced users, you can even define your own css for the group labeling.

kable(dt, "html") %>%
  kable_styling("striped", full_width = F) %>%
  add_indent(c(1, 3, 5))
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440

Group rows via multi-row cell

Function group_rows is great for showing simple structural information on rows but sometimes people may need to show structural information with multiple layers. When it happens, you may consider to use collapse_rows instead, which will put repeating cells in columns into multi-row cells.

collapse_rows_dt <- data.frame(C1 = c(rep("a", 10), rep("b", 5)),
                 C2 = c(rep("c", 7), rep("d", 3), rep("c", 2), rep("d", 3)),
                 C3 = 1:15,
                 C4 = sample(c(0,1), 15, replace = TRUE))
kable(collapse_rows_dt, "html", align = "c") %>%
  kable_styling(full_width = F) %>%
  column_spec(1, bold = T) %>%
  collapse_rows(columns = 1:2)
C1 C2 C3 C4
a c 1 1
2 1
3 0
4 1
5 1
6 1
7 1
d 8 1
9 1
10 1
b c 11 0
12 0
d 13 0
14 1
15 0

Table Footnote

Notation systems

You can also use add_footnote() function from this package. You will need to supply a character vector with each element as one footnote. You may select from number, alphabet and symbol for different types of notations. Example are listed below.

Alphabet

kable(dt, "html") %>%
  kable_styling("striped") %>%
  add_footnote(c("Footnote 1", "Have a good day."), notation = "alphabet")
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440
a Footnote 1
b Have a good day.

Number

kable(dt, "html") %>%
  kable_styling("striped") %>%
  add_footnote(c("Footnote 1", "Have a good day."), notation = "number")
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440
1 Footnote 1
2 Have a good day.

Symbol

kable(dt, "html") %>%
  kable_styling("striped") %>%
  add_footnote(c("Footnote 1", "Footnote 2", "Footnote 3"), notation = "symbol")
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440
* Footnote 1
† Footnote 2
‡ Footnote 3

In-table markers

By design, add_footnote() will transform any [note] to in-table footnote markers.

kable(dt, "html", caption = "Demo Table[note]") %>%
  kable_styling("striped") %>%
  add_header_above(c(" ", "Group 1[note]" = 3, "Group 2[note]" = 3)) %>%
  add_footnote(c("This table is from mtcars", 
                 "Group 1 contains mpg, cyl and disp", 
                 "Group 2 contains hp, drat and wt"), 
               notation = "symbol")
Demo Table*
Group 1†
Group 2‡
mpg cyl disp hp drat wt
Mazda RX4 21.0 6 160 110 3.90 2.620
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875
Datsun 710 22.8 4 108 93 3.85 2.320
Hornet 4 Drive 21.4 6 258 110 3.08 3.215
Hornet Sportabout 18.7 8 360 175 3.15 3.440
* This table is from mtcars
† Group 1 contains mpg, cyl and disp
‡ Group 2 contains hp, drat and wt

HTML Only Features

Scroll box

If you have a huge table and you don’t want to reduce the font size to unreadable, you may want to put your HTML table in a scroll box, of which users can pick the part they like to read. Note that scroll box isn’t printer friendly, so be aware of that when you use this feature.

When you use scroll_box, you can specify either height or width. When you specify height, you will get a vertically scrollable box and vice versa. If you specify both, you will get a two-way scrollable box.

kable(cbind(mtcars, mtcars), "html") %>%
  kable_styling() %>%
  scroll_box(width = "500px", height = "200px")
mpg cyl disp hp drat wt qsec vs am gear carb mpg cyl disp hp drat wt qsec vs am gear carb
Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4
Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4
Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1
Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1
Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2
Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1
Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2
Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2
Merc 280 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4
Merc 280C 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4 4 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4 4
Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3
Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3
Merc 450SLC 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3
Cadillac Fleetwood 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4
Lincoln Continental 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4
Chrysler Imperial 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4
Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1
Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2
Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1
Toyota Corona 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1
Dodge Challenger 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3 2 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3 2
AMC Javelin 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2
Camaro Z28 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4
Pontiac Firebird 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2
Fiat X1-9 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1
Porsche 914-2 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2
Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2
Ford Pantera L 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4
Ferrari Dino 19.7 6 145.0 175 3.62 2.770 15.50 0 1 5 6 19.7 6 145.0 175 3.62 2.770 15.50 0 1 5 6
Maserati Bora 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8
Volvo 142E 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2