Horizontal Box Plot — Pygal

A horizontal box plot displays the distribution of numerical data through quartiles with the boxes oriented horizontally. This orientation is particularly useful when category labels are long or when comparing many groups, as it allows for easier reading of labels on the y-axis.

Horizontal Box Plot rendered with Pygal

Python source (Pygal)

""" anyplot.ai
box-horizontal: Horizontal Box Plot
Library: pygal 3.1.0 | Python 3.13.13
Quality: 83/100 | Updated: 2026-05-12
"""

import os

import numpy as np
import pygal
from pygal.style import Style


THEME = os.getenv("ANYPLOT_THEME", "light")
PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
INK_MUTED = "#6B6A63" if THEME == "light" else "#A8A79F"

IMPRINT = ("#009E73", "#C475FD", "#4467A3", "#BD8233", "#AE3030")

# Data - Salary ranges by job title
np.random.seed(42)
categories = ["Software Engineer", "Data Scientist", "Product Manager", "Designer", "DevOps Engineer"]
data = {
    "Software Engineer": np.random.normal(125000, 20000, 100),
    "Data Scientist": np.random.normal(130000, 22000, 100),
    "Product Manager": np.random.normal(140000, 25000, 100),
    "Designer": np.random.normal(105000, 18000, 100),
    "DevOps Engineer": np.random.normal(135000, 21000, 100),
}

# Custom style using theme-adaptive tokens
custom_style = Style(
    background=PAGE_BG,
    plot_background=PAGE_BG,
    foreground=INK,
    foreground_strong=INK,
    foreground_subtle=INK_MUTED,
    colors=IMPRINT,
    title_font_size=28,
    label_font_size=22,
    major_label_font_size=18,
    legend_font_size=16,
    value_font_size=14,
    stroke_width=3,
)

# Create horizontal box dynamically (pygal doesn't include HorizontalBox natively)
HorizontalBox = type("HorizontalBox", (pygal.graph.horizontal.HorizontalGraph, pygal.graph.box.Box), {})

# Create chart
chart = HorizontalBox(
    width=4800,
    height=2700,
    style=custom_style,
    title="box-horizontal · pygal · anyplot.ai",
    x_title="Salary (USD)",
    show_legend=True,
    show_y_guides=True,
    show_x_guides=False,
    margin=80,
    margin_left=300,
    margin_bottom=120,
    box_mode="tukey",
)

# Set category labels on y-axis
chart.x_labels = categories

# Add data for each category
for category in categories:
    chart.add(category, data[category].tolist())

# Save outputs
chart.render_to_file(f"plot-{THEME}.html")
chart.render_to_png(f"plot-{THEME}.png")

Part of Horizontal Box Plot on anyplot.ai.

Other implementations