Violin Plots

What is a violin plot?

A violin plot combines:

• A KDE distribution shape
• A box-plot-like summary inside

It’s useful when you want to see the shape of distributions (multi-modal, skew).

diagram Violin = box plot + KDE mermaid

  flowchart LR
  A["Numeric column
per category"] --> B["Compute KDE
for each category"]
  B --> C["Mirror the KDE curve
left and right"]
  C --> D["Overlay a mini box
plot in the middle"]

A violin plot mirrors a KDE curve left and right to form a shape, with a mini box plot drawn down the middle.

Note

A box plot only shows five numbers (min, Q1, median, Q3, max). A violin plot shows the entire shape of the distribution, so it can reveal things a box plot hides — like two separate peaks (bimodal data) that would otherwise look like one wide box.

Violin plot in Seaborn

Violin plot

import seaborn as sns
import matplotlib.pyplot as plt
 
tips = sns.load_dataset("tips")
 
plt.figure(figsize=(7, 4))
sns.violinplot(data=tips, x="day", y="total_bill")
plt.title("Total bill distribution by day")
plt.tight_layout()
plt.show()

Add inner summary

Violin with inner quartiles

import seaborn as sns
import matplotlib.pyplot as plt
 
tips = sns.load_dataset("tips")
 
plt.figure(figsize=(7, 4))
sns.violinplot(data=tips, x="day", y="total_bill", inner="quartile")
plt.title("Violin plot with quartiles")
plt.tight_layout()
plt.show()

Visualize it

The width of the violin at any height shows how common values near that height are — wider means more data points cluster there:

sketch Anatomy of a violin plot p5.js Pause Restart

The violin's width at each height mirrors the KDE density; the inner bar is a mini box plot.

When to prefer violin vs box

• Use box plots for quick comparisons and outlier focus.
• Use violin plots when the distribution shape matters.

Next

Continue to Bar Plots in Seaborn to compare an aggregated value (like a mean) across categories, with confidence intervals.

🧪 Try It Yourself

Exercise 1 – A Basic Violin Plot

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Exercise 2 – Show Quartiles Inside

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Exercise 3 – Box vs Violin

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