Configuration Options

Presentation behavior can be fine-tuned using a wide array of configuration options. These objects can be included where you initialize reveal.js. It's also possible to change config values at runtime.

Note that all configuration values are optional and will default to the values specified below.

Reveal.initialize({
  // Display presentation control arrows
  controls: true,

  // Help the user learn the controls by providing hints, for example by
  // bouncing the down arrow when they first encounter a vertical slide
  controlsTutorial: true,

  // Determines where controls appear, "edges" or "bottom-right"
  controlsLayout: 'bottom-right',

  // Visibility rule for backwards navigation arrows; "faded", "hidden"
  // or "visible"
  controlsBackArrows: 'faded',

  // Display a presentation progress bar
  progress: true,

  // Display the page number of the current slide
  // - true:    Show slide number
  // - false:   Hide slide number
  //
  // Can optionally be set as a string that specifies the number formatting:
  // - "h.v":   Horizontal . vertical slide number (default)
  // - "h/v":   Horizontal / vertical slide number
  // - "c":   Flattened slide number
  // - "c/t":   Flattened slide number / total slides
  //
  // Alternatively, you can provide a function that returns the slide
  // number for the current slide. The function should take in a slide
  // object and return an array with one string [slideNumber] or
  // three strings [n1,delimiter,n2]. See #formatSlideNumber().
  slideNumber: false,

  // Can be used to limit the contexts in which the slide number appears
  // - "all":      Always show the slide number
  // - "print":    Only when printing to PDF
  // - "speaker":  Only in the speaker view
  showSlideNumber: 'all',

  // Use 1 based indexing for # links to match slide number (default is zero
  // based)
  hashOneBasedIndex: false,

  // Add the current slide number to the URL hash so that reloading the
  // page/copying the URL will return you to the same slide
  hash: false,

  // Flags if we should monitor the hash and change slides accordingly
  respondToHashChanges: true,

  // Enable support for jump-to-slide navigation shortcuts
  jumpToSlide: true,

  // Push each slide change to the browser history.  Implies `hash: true`
  history: false,

  // Enable keyboard shortcuts for navigation
  keyboard: true,

  // Optional function that blocks keyboard events when retuning false
  //
  // If you set this to 'focused', we will only capture keyboard events
  // for embedded decks when they are in focus
  keyboardCondition: null,

  // Disables the default reveal.js slide layout (scaling and centering)
  // so that you can use custom CSS layout
  disableLayout: false,

  // Enable the slide overview mode
  overview: true,

  // Vertical centering of slides
  center: true,

  // Enables touch navigation on devices with touch input
  touch: true,

  // Loop the presentation
  loop: false,

  // Change the presentation direction to be RTL
  rtl: false,

  // Changes the behavior of our navigation directions.
  //
  // "default"
  // Left/right arrow keys step between horizontal slides, up/down
  // arrow keys step between vertical slides. Space key steps through
  // all slides (both horizontal and vertical).
  //
  // "linear"
  // Removes the up/down arrows. Left/right arrows step through all
  // slides (both horizontal and vertical).
  //
  // "grid"
  // When this is enabled, stepping left/right from a vertical stack
  // to an adjacent vertical stack will land you at the same vertical
  // index.
  //
  // Consider a deck with six slides ordered in two vertical stacks:
  // 1.1    2.1
  // 1.2    2.2
  // 1.3    2.3
  //
  // If you're on slide 1.3 and navigate right, you will normally move
  // from 1.3 -> 2.1. If "grid" is used, the same navigation takes you
  // from 1.3 -> 2.3.
  navigationMode: 'default',

  // Randomizes the order of slides each time the presentation loads
  shuffle: false,

  // Turns fragments on and off globally
  fragments: true,

  // Flags whether to include the current fragment in the URL,
  // so that reloading brings you to the same fragment position
  fragmentInURL: true,

  // Flags if the presentation is running in an embedded mode,
  // i.e. contained within a limited portion of the screen
  embedded: false,

  // Flags if we should show a help overlay when the question-mark
  // key is pressed
  help: true,

  // Flags if it should be possible to pause the presentation (blackout)
  pause: true,

  // Flags if speaker notes should be visible to all viewers
  showNotes: false,

  // Global override for autolaying embedded media (video/audio/iframe)
  // - null:   Media will only autoplay if data-autoplay is present
  // - true:   All media will autoplay, regardless of individual setting
  // - false:  No media will autoplay, regardless of individual setting
  autoPlayMedia: null,

  // Global override for preloading lazy-loaded iframes
  // - null:   Iframes with data-src AND data-preload will be loaded when within
  //           the viewDistance, iframes with only data-src will be loaded when visible
  // - true:   All iframes with data-src will be loaded when within the viewDistance
  // - false:  All iframes with data-src will be loaded only when visible
  preloadIframes: null,

  // Can be used to globally disable auto-animation
  autoAnimate: true,

  // Optionally provide a custom element matcher that will be
  // used to dictate which elements we can animate between.
  autoAnimateMatcher: null,

  // Default settings for our auto-animate transitions, can be
  // overridden per-slide or per-element via data arguments
  autoAnimateEasing: 'ease',
  autoAnimateDuration: 1.0,
  autoAnimateUnmatched: true,

  // CSS properties that can be auto-animated. Position & scale
  // is matched separately so there's no need to include styles
  // like top/right/bottom/left, width/height or margin.
  autoAnimateStyles: [
    'opacity',
    'color',
    'background-color',
    'padding',
    'font-size',
    'line-height',
    'letter-spacing',
    'border-width',
    'border-color',
    'border-radius',
    'outline',
    'outline-offset',
  ],

  // Controls automatic progression to the next slide
  // - 0:      Auto-sliding only happens if the data-autoslide HTML attribute
  //           is present on the current slide or fragment
  // - 1+:     All slides will progress automatically at the given interval
  // - false:  No auto-sliding, even if data-autoslide is present
  autoSlide: 0,

  // Stop auto-sliding after user input
  autoSlideStoppable: true,

  // Use this method for navigation when auto-sliding (defaults to navigateNext)
  autoSlideMethod: null,

  // Specify the average time in seconds that you think you will spend
  // presenting each slide. This is used to show a pacing timer in the
  // speaker view
  defaultTiming: null,

  // Enable slide navigation via mouse wheel
  mouseWheel: false,

  // Opens links in an iframe preview overlay
  // Add `data-preview-link` and `data-preview-link="false"` to customise each link
  // individually
  previewLinks: false,

  // Exposes the reveal.js API through window.postMessage
  postMessage: true,

  // Dispatches all reveal.js events to the parent window through postMessage
  postMessageEvents: false,

  // Focuses body when page changes visibility to ensure keyboard shortcuts work
  focusBodyOnPageVisibilityChange: true,

  // Transition style
  transition: 'slide', // none/fade/slide/convex/concave/zoom

  // Transition speed
  transitionSpeed: 'default', // default/fast/slow

  // Transition style for full page slide backgrounds
  backgroundTransition: 'fade', // none/fade/slide/convex/concave/zoom

  // The maximum number of pages a single slide can expand onto when printing
  // to PDF, unlimited by default
  pdfMaxPagesPerSlide: Number.POSITIVE_INFINITY,

  // Prints each fragment on a separate slide
  pdfSeparateFragments: true,

  // Offset used to reduce the height of content within exported PDF pages.
  // This exists to account for environment differences based on how you
  // print to PDF. CLI printing options, like phantomjs and wkpdf, can end
  // on precisely the total height of the document whereas in-browser
  // printing has to end one pixel before.
  pdfPageHeightOffset: -1,

  // Number of slides away from the current that are visible
  viewDistance: 3,

  // Number of slides away from the current that are visible on mobile
  // devices. It is advisable to set this to a lower number than
  // viewDistance in order to save resources.
  mobileViewDistance: 2,

  // The display mode that will be used to show slides
  display: 'block',

  // Hide cursor if inactive
  hideInactiveCursor: true,

  // Time before the cursor is hidden (in ms)
  hideCursorTime: 5000,
});

Reconfiguring

The configuration can be updated after initialization using the configure method.

// Turn autoSlide off
Reveal.configure({ autoSlide: 0 });

// Start auto-sliding every 5s
Reveal.configure({ autoSlide: 5000 });