Format for converting from R Markdown to an ioslides presentation.

  number_sections = FALSE,
  logo = NULL,
  slide_level = 2,
  incremental = FALSE,
  fig_width = 7.5,
  fig_height = 4.5,
  fig_retina = 2,
  fig_caption = TRUE,
  dev = "png",
  df_print = "default",
  smart = TRUE,
  self_contained = TRUE,
  widescreen = FALSE,
  smaller = FALSE,
  transition = "default",
  math_method = "mathjax",
  mathjax = "default",
  analytics = NULL,
  template = NULL,
  css = NULL,
  includes = NULL,
  keep_md = FALSE,
  lib_dir = NULL,
  md_extensions = NULL,
  pandoc_args = NULL,
  extra_dependencies = NULL,



TRUE to number section headings


Path to file that includes a logo for use in the presentation (should be square and at least 128x128).


Header level to consider as slide separator (Defaults to header 2).


TRUE to render slide bullets incrementally. Note that if you want to reverse the default incremental behavior for an individual bullet you can preceded it with >. For example: > - Bullet Text.


Default width (in inches) for figures


Default height (in inches) for figures


Scaling to perform for retina displays (defaults to 2, which currently works for all widely used retina displays). Set to NULL to prevent retina scaling. Note that this will always be NULL when keep_md is specified (this is because fig_retina relies on outputting HTML directly into the markdown document).


TRUE to render figures with captions


Graphics device to use for figure output (defaults to png)


Method to be used for printing data frames. Valid values include "default", "kable", "tibble", and "paged". The "default" method uses a corresponding S3 method of print, typically The "kable" method uses the knitr::kable function. The "tibble" method uses the tibble package to print a summary of the data frame. The "paged" method creates a paginated HTML table (note that this method is only valid for formats that produce HTML). In addition to the named methods you can also pass an arbitrary function to be used for printing data frames. You can disable the df_print behavior entirely by setting the option rmarkdown.df_print to FALSE. See Data frame printing section in bookdown book for examples.


Produce typographically correct output, converting straight quotes to curly quotes, --- to em-dashes, -- to en-dashes, and ... to ellipses.


Produce a standalone HTML file with no external dependencies, using data: URIs to incorporate the contents of linked scripts, stylesheets, images, and videos. Note that even for self contained documents MathJax is still loaded externally (this is necessary because of its size).


Display presentation with wider dimensions.


Use smaller text on all slides. You can also enable this for individual slides by adding the .smaller attribute to the slide header (see Presentation Size below for details).


Speed of slide transitions. This can be "default", "slower", "faster", or a numeric value with a number of seconds (e.g. 0.5).


Math rendering engine to use. This will define the math method to use with Pandoc.

  • It can be a string for the engine, one of "mathjax", "mathml", "webtex", "katex", "gladtex", or "r-katex" or "default" for mathjax.

  • It can be a list of

    • engine: one of "mathjax", "mathml", "webtex", "katex", or "gladtex".

    • url: A specific url to use with mathjax, katex or webtex. Note that for engine = "mathjax", url = "local" will use a local version of MathJax (which is copied into the output directory).

For example,

      engine: katex

See Pandoc's Manual about Math in HTML for the details about Pandoc supported methods.

Using math_method = "r-katex" will opt-in server side rendering using KaTeX thanks to katex R package. This is useful compared to math_method = "katex" to have no JS dependency, only a CSS dependency for styling equation.


Include mathjax. The "default" option uses an https URL from a MathJax CDN. The "local" option uses a local version of MathJax (which is copied into the output directory). You can pass an alternate URL or pass NULL to exclude MathJax entirely.


A Google analytics property ID.


Pandoc template to use for rendering. Pass "default" to use the rmarkdown package default template; pass NULL to use pandoc's built-in template; pass a path to use a custom template that you've created. Note that if you don't use the "default" template then some features of html_document won't be available (see the Templates section below for more details).


One or more css files to include.


Named list of additional content to include within the document (typically created using the includes function).


Keep the markdown file generated by knitting.


Directory to copy dependent HTML libraries (e.g. jquery, bootstrap, etc.) into. By default this will be the name of the document with _files appended to it.


Markdown extensions to be added or removed from the default definition of R Markdown. See the rmarkdown_format for additional details.


Additional command line options to pass to pandoc


Extra dependencies as a list of the html_dependency class objects typically generated by htmltools:htmlDependency().


Additional function arguments to pass to the base R Markdown HTML output formatter html_document_base


R Markdown output format to pass to render().


See the online documentation for additional details on using the ioslides_presentation format.

Note that, if a before_body include is specified in includes, then it will replace the standard title slide entirely.

Regarding previewing slide in RStudio IDE, ioslides_presentation() will always open preview in a new Window and the RStudio IDE configuration "Open in Viewer Pane" will have no effect for this format.

Slide Basics

You can create a slide show broken up into sections by using the # and ## heading tags (you can also create a new slide without a header using a horizontal rule (----------). For example here's a simple slide show:

title: "Habits"
author: John Doe
date: March 22, 2005
output: ioslides_presentation

# In the morning

## Getting up

- Turn off alarm
- Get out of bed

## Breakfast

- Eat eggs
- Drink coffee

# In the evening

## Dinner

- Eat spaghetti
- Drink wine


![picture of spaghetti](images/spaghetti.jpg)

## Going to sleep

- Get in bed
- Count sheep

You can add a subtitle to a slide or section by including text after the pipe (|) character. For example:

## Getting up | What I like to do first thing

Display Modes

The following single character keyboard shortcuts enable alternate display modes:


enable fullscreen mode


toggle widescreen mode


enable overview mode


enable code highlight mode


show presenter notes

Pressing Esc exits all of these modes. See the sections below on Code Highlighting and Presenter Mode for additional detail on those modes.

Incremental Bullets

You can render bullets incrementally by adding the incremental option:

    incremental: true

If you want to render bullets incrementally for some slides but not others you can use this syntax:

> - Eat eggs
> - Drink coffee

Presentation Size

You can display the presentation using a wider form factor using the widescreen option. You can specify that smaller text be used with the smaller option. For example:

    widescreen: true
    smaller: true

You can also enable the smaller option on a slide-by-slide basis by adding the .smaller attribute to the slide header:

## Getting up {.smaller}

Build Slides

Slides can also have a .build attribute that indicate that their content should be displayed incrementally. For example:

## Getting up {.build}

Slide attributes can be combined if you need to specify more than one, for example:

## Getting up {.smaller .build}

Code Highlighting

It's possible to select subsets of code for additional emphasis by adding a special "highlight" comment around the code. For example:

### <b>
x <- 10
y <- x * 2
### </b>

The highlighted region will be displayed with a bold font. When you want to help the audience focus exclusively on the highlighted region press the 'h' key and the rest of the code will fade away.


The ioslides template has an attractive default style for tables so you shouldn't hesitate to add tables for presenting more complex sets of information. Pandoc markdown supports several syntaxes for defining tables which are described in the pandoc online documentation.

Advanced Layout

You can center content on a slide by adding the .flexbox and .vcenter attributes to the slide title. For example:

## Dinner {.flexbox .vcenter}

You can horizontally center content by enclosing it in a div tag with class centered. For example:

<div class="centered">
This text is centered.

You can do a two-column layout using the columns-2 class. For example:

<div class="columns-2">

  - Bullet 1
  - Bullet 2
  - Bullet 3

Note that content will flow across the columns so if you want to have an image on one side and text on the other you should make sure that the image has sufficient height to force the text to the other side of the slide.

Text Color

You can color content using base color classes red, blue, green, yellow, and gray (or variations of them e.g. red2, red3, blue2, blue3, etc.). For example:

<div class="red2">
This text is red

Presenter Mode

A separate presenter window can also be opened (ideal for when you are presenting on one screen but have another screen that's private to you). The window stays in sync with the main presentation window and also shows presenter notes and a thumbnail of the next slide. To enable presenter mode add ?presentme=true to the URL of the presentation, for example:


The presenter mode window will open and will always re-open with the presentation until it's disabled with:


To add presenter notes to a slide you include it within a "notes" div. For example:

<div class="notes">
This is my *note*.

- It can contain markdown
- like this list


Printing and PDF Output

You can print an ioslides presentation from within browsers that have good support for print CSS (i.e. as of this writing Google Chrome has the best support). Printing maintains most of the visual styles of the HTML version of the presentation.

To create a PDF version of a presentation you can use Print to PDF from Google Chrome.