Stacked Histogram — Matplotlib

A histogram showing multiple groups stacked on top of each other within each bin. The total bar height represents the combined frequency, while colored segments show individual group contributions.

Stacked Histogram rendered with Matplotlib

Python source (Matplotlib)

""" anyplot.ai
histogram-stacked: Stacked Histogram
Library: matplotlib 3.10.9 | Python 3.13.13
Quality: 93/100 | Updated: 2026-05-12
"""

import os

import matplotlib.pyplot as plt
import numpy as np


# Theme tokens
THEME = os.getenv("ANYPLOT_THEME", "light")
PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
ELEVATED_BG = "#FFFDF6" if THEME == "light" else "#242420"
INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
INK_SOFT = "#4A4A44" if THEME == "light" else "#B8B7B0"

# Okabe-Ito palette - using first 3 colors in canonical order
IMPRINT = ["#009E73", "#C475FD", "#4467A3"]

# Data - Response times (ms) for three different server regions
np.random.seed(42)

us_east = np.random.normal(loc=45, scale=12, size=200)
europe = np.random.normal(loc=65, scale=15, size=180)
asia = np.random.normal(loc=80, scale=20, size=150)

us_east = np.clip(us_east, 10, 120)
europe = np.clip(europe, 15, 140)
asia = np.clip(asia, 20, 160)

labels = ["US-East", "Europe", "Asia-Pacific"]

# Plot
fig, ax = plt.subplots(figsize=(16, 9), facecolor=PAGE_BG)
ax.set_facecolor(PAGE_BG)

ax.hist(
    [us_east, europe, asia],
    bins=20,
    stacked=True,
    color=IMPRINT,
    label=labels,
    edgecolor=PAGE_BG,
    linewidth=0.5,
    alpha=0.9,
)

# Style
ax.set_xlabel("Response Time (ms)", fontsize=20, color=INK)
ax.set_ylabel("Number of Requests", fontsize=20, color=INK)
ax.set_title("histogram-stacked · matplotlib · anyplot.ai", fontsize=24, fontweight="medium", color=INK)
ax.tick_params(axis="both", labelsize=16, colors=INK_SOFT)

for s in ("top", "right"):
    ax.spines[s].set_visible(False)
for s in ("left", "bottom"):
    ax.spines[s].set_color(INK_SOFT)

ax.yaxis.grid(True, alpha=0.10, linewidth=0.8, color=INK)

leg = ax.legend(fontsize=16, loc="upper right", frameon=True)
if leg:
    leg.get_frame().set_facecolor(ELEVATED_BG)
    leg.get_frame().set_edgecolor(INK_SOFT)
    leg.get_frame().set_linewidth(0.8)
    plt.setp(leg.get_texts(), color=INK_SOFT)

plt.tight_layout()
plt.savefig(f"plot-{THEME}.png", dpi=300, bbox_inches="tight", facecolor=PAGE_BG)

Part of Stacked Histogram on anyplot.ai.

Other implementations