Plot Twist

Adding Interactivity to the
Elegance of {ggplot2} with {ggiraph}

Tanya Shapiro & Cédric Scherer
useR 2025

Hi, I'm Tanya

BEFORE
Data Professional with
Insurance Background

NOW
Founder, Consultant IndieVisual

Hi, I'm Cédric

BEFORE
PhD in Computational Ecology

NOW
Data Visualization
Designer, Consultant & Educator

Why we ❤️ ggplot2

A collection of extension packages for (and built with) ggplot2. A wild mixture of the most popular packages, packages for very specific use cases, packages that provide color palettes, and very experimental stuff.

An illustration by Allison Horst: A person in a cape that reads “code hero” who looks like they are flying through the air while typing on a computer while saying “I’m doing a think all on my own!” The coder’s arms and legs have ropes attached to two hot air balloons lifting them up, with labels on the balloons including “teachers”, “bloggers”, “friends”, “developers”. Below the code hero, several people carry a trampoline with labels “support” and “community” that will catch them if they fall.

Why go interactive?

Static plots tell a story.

Interactive plots invite people to explore the story!

Where To Start?

Goldilocks trying to find the right fit for interactive viz

The ggiraph Philosophy

If you know ggplot2…
you already know ggiraph

Plausible quote from Hadley Wickham,
Father of ggplot2

50 interactive ggiraph geoms!

Consistent naming convention to match ggplot2 geoms

ggplot2		ggiraph
geom_point	➡️	geom_point_interactive
geom_text	➡️	geom_text_interactive
geom_line	➡️	geom_line_interactive
geom_tile	➡️	geom_tile_interactive

Export result directly as HTML widgets —
or use with Quarto, R Markdown, or Shiny 🙌

Examples: Tooltips

Setting up Tooltips

p <- ggplot(simpsons_imdb, aes(x = episode, y = season, fill = rating)) +
  geom_tile_interactive(
    aes(tooltip = title, data_id = id), 
    color = "white", stroke = .2
  ) +
  geomtextpath::geom_texthline(...) +
  ...

girafe(
  ggobj = p,
  options = list(
    opts_tooltip(
      opacity = 1, use_fill = TRUE,
      css = "color: black; padding: 15px;"
    ),
    opts_hover(css = "stroke-width: 1;"),
    opts_hover_inv(css = "opacity: 0.3;")
  )
)

Create More Advanced Tooltips

p <- 
  simpsons_imdb |> 
  mutate(
    title_wrapped = stringr::str_replace_all(stringr::str_wrap(title, 22), "\\n", "<br>"),
    text_color = if_else(rating > 6.3 & rating < 8.5, "black", "white"),
    tooltip_text = paste0(
      "<span style='font-family:rethink sans;color:", text_color, ";'>", 
      "S", sprintf("%02d", season), " E", sprintf("%02d", episode), "<br>",
      "<b style='font-size:150%;font-weight:600;font-family:piazzolla;'>", 
      title_wrapped, "</b><br><br>", "
      IMDb Rating: ", sprintf("%1.1f", rating))
  ) |> 
  ggplot(aes(x = episode, y = season, fill = rating)) +
  geom_tile_interactive(
    aes(tooltip = tooltip_text, data_id = id), 
    color = "white", stroke = .2
  ) +
  geomtextpath::geom_texthline(...) +
  ...

girafe(
  ggobj = p,
  options = list(
    opts_tooltip(
      opacity = 1, use_fill = TRUE,
      css = "color: black; padding: 15px;"
    ),
    opts_hover(css = "stroke-width: 1;"),
    opts_hover_inv(css = "opacity: 0.3;")
  )
)

Example: Hovering

Basic Hover Effects

doctor_who_basic_plot<-ggplot() +
   #interactive points per episode
   ggiraph::geom_jitter_interactive(
     data = df_eps,
     position = position_jitter(seed = 42, height = .2, width = 3),
     mapping = aes(
       data_id = story_number,
       x = rating,
       y = reorder(doctor, avg_rating),
       fill = I(color),
       tooltip = tooltip
     ),
     shape = 21,
     color = "black",
     size = 3,
     alpha = 0.8
   ) +
   geomtextpath::geom_textvline(
     mapping = aes(
       xintercept = overall_avg,
       label = paste0("Overall Avg: ", round(overall_avg, 0))
     ),
     size = 3,
     color = pal_line,
     hjust = 0.86,
     vjust = -.2,
     family = "Roboto"
   ) +
   geom_segment(
     data = df_doc_avg,
     mapping = aes(
       x = avg_rating,
       xend = overall_avg,
       y = doctor,
       yend = doctor
     ),
     color = pal_line
   ) +
   geom_point(
     data = df_doc_avg,
     mapping = aes(x = avg_rating, y = doctor, fill = I(color)),
     shape = 21, 
     color = "white",
     size = 10
   ) +
   geom_image(
     data = df_doc_avg,
     mapping = aes(x = avg_rating, y = doctor, image = image),
     size = 0.06,
     asp = 1.61
   ) +
   geom_text(
     data = df_doc_avg,
     mapping = aes(
       x = avg_rating,
       y = doctor,
       label = round(avg_rating, 1)
     ),
     size = 2.5,
     fontface= "bold",
     color = "white",
     vjust = 3.75,
     family = "Roboto"
   ) +
   geom_textbox(
     data = df_doc_avg,
     mapping = aes(x = 59.1, y = doctor, label = label),
     family = "Roboto",
     fill = NA,
     box.size = NA,
     box.padding = unit(rep(0, 4), "pt"),
     color = pal_text,
     hjust = 0
   ) +
   #arrows
   annotate(
     geom = "text",
     label = "Avg Rating\nper Doctor",
     x = 76,
     y = 2.5,
     size = 2.5,
     color = "white",
     family = "Roboto"
   ) +
   geom_curve(
     mapping = aes(
       x = 77,
       xend = 81.4,
       y = 2.7,
       yend = 3
     ),
     color = "white",
     curvature = -0.2,
     linewidth = 0.3,
     arrow = arrow(length = unit(0.08, "in"))
   ) +
   geom_curve(
     mapping = aes(
       x = 77,
       xend = 80.8,
       y = 2.3,
       yend = 2
     ),
     color = "white",
     curvature = 0.2,
     linewidth = 0.3,
     arrow = arrow(length = unit(0.08, "in"))
   ) +
   scale_x_continuous(
     limits = c(59, 95),
     expand = c(0, 0),
     breaks = c(70, 75, 80, 85, 90, 95)
   ) +
   coord_equal(ratio = 50 / 12) +
   labs(
     title = "Doctor Who was The Best?",
     subtitle = "Ratings by Episode and Doctor for the popular TV series, Doctor Who.",
     x = "Rating"
   )+
   theme(
     legend.position = "none",
     plot.background = element_rect(fill = pal_bg, color = pal_bg),
     panel.background = element_blank(),
     panel.grid = element_blank(),
     plot.margin = margin(
       l = 20,
       r = 40,
       b = 10,
       t = 20
     ),
     plot.caption = element_text(size = 7, color = "grey80"),
     plot.title = element_text(
       size = 14,
       face = "bold",
       margin = margin(b = 5)
     ),
     plot.subtitle  = element_text(size = 9, color = "#BABABA"),
     text = element_text(color = pal_text, family = "Roboto"),
     axis.text = element_text(color = pal_text, family = "Roboto Mono"),
     axis.text.y = element_blank(),
     axis.title.y = element_blank(),
     axis.title.x = element_textbox_simple(
       margin = margin(t = 10),
       halign = 0.675,
       hjust = 0.5
     ),
     axis.ticks = element_blank()
   )
 


 ggiraph::girafe(
   ggobj = doctor_who_basic_plot,
   options = list(
      ggiraph::opts_toolbar(saveaspng = FALSE),
      ggiraph::opts_tooltip(css = "font-family:Roboto;"),
      #modify hover css
      ggiraph::opts_hover(css = "fill:white;stroke:grey;cursor:help;")
      )
   )

Advanced Hover Effects

ggiraph::girafe(
  ggobj = doctor_who_advanced_plot,
  width_svg = 6.125, height_svg = 4.5,
  options = list(
    #turnoff download png
    ggiraph::opts_toolbar(saveaspng = FALSE),
    ggiraph::opts_sizing(width = .8),
    #default tooltip font
    ggiraph::opts_tooltip(
      css = "font-family:Roboto;"
    ),
    #remove default opts_hover settings
    ggiraph::opts_hover(css=""),
    #inverted hover, use girafe_css for more control on hover elements
    ggiraph::opts_hover_inv(
      girafe_css(
        css = "", 
        point = "fill:#515151",
        text = NULL
      )
    )
  )
)

…a creative use case with ggiraph hover

👀

Example: Combo Plots

Linking Data Across Plots

Combo Plot with {patchwork}

plot_owid <- ggplot(data = owid_urban, ...) +
  geom_point_interactive(
    aes(tooltip = tooltip, data_id = country, color = continent), 
    shape = 16, alpha = .72
  ) +
  ...

map_owid <- ggplot(data = owid_urban, ...) +
  geom_sf_interactive(
    aes(tooltip = tooltip, data_id = country, fill = continent), 
    color = "transparent", linewidth = .2
  ) 
  ...

combined_owid <- plot_owid + map_owid +
  plot_layout(ncol = 2, widths = c(.4, .6))

girafe(
  ggobj = combined_owid, width_svg = 12, height_svg = 5.3,
  options = list(
    opts_tooltip(use_fill = TRUE, css = "
    font-size: 17px;
    font-weight: 400;
    font-family: Spline Sans;
    color:white;
    padding: 10px;
    border:2px solid white;
    border-radius: 5px;
    "),
    opts_hover(css = "stroke: white; stroke-width: 0.5px; opacity: 1;"),
    opts_hover_inv(css = "opacity: 0.2;"),
    opts_toolbar(position = "bottomright"),
    opts_zoom(min = 1, max = 4)
  )
)

Example: Shiny

Thank you!

Want to learn more?

Code Examples 👉 github.com/z3tt/ggiraph-user-2025 ggiraph Book by David Gohel 👉 ardata.fr/ggiraph-book

Fancy a workshop or collaboration?

We are always open for consulting and trainings!

 tanya@indievisual.tech    viz@cedricscherer.com

ggplot2-uncharted.com