Custom linewidth

Customizing your boxplot's linewidth is really straightforward and quickly done through the linewidth argument.

Customizing boxplots appearance with Seaborn: Custom linewidth

# libraries & dataset
import seaborn as sns
import matplotlib.pyplot as plt
  
sns.set_theme(style="darkgrid")
df = sns.load_dataset('iris')

sns.boxplot(x=df["species"], y=df["sepal_length"], linewidth=5)
plt.show()

Add notch

Customizing boxplots appearance with Seaborn: Add notch

# libraries & dataset
import seaborn as sns
import matplotlib.pyplot as plt
  
sns.set_theme(style="darkgrid")
df = sns.load_dataset('iris')

sns.boxplot(x=df["species"], y=df["sepal_length"], notch=True)
plt.show()

Controlling box size

This can be an interesting modification in the case where you are facing with multiple categories to display in the same figure, given that space is limited.

Customizing boxplots appearance with Seaborn: Controlling box size

# libraries & dataset
import seaborn as sns
import matplotlib.pyplot as plt
  
sns.set_theme(style="darkgrid")
df = sns.load_dataset('iris')

sns.boxplot(x=df["species"], y=df["sepal_length"], width=0.3)
plt.show()