How to change plotly figure size

Plotly allows you to create interactive, publication-quality figures in Python. You can customize the width and height of your figures through multiple approaches: using update_layout, Plotly Express parameters, default templates, or configuration options when exporting. This guide covers each method with code examples.

1. Using update_layout

The most direct method is setting the width and height properties on the figure’s layout.

import plotly.graph_objects as go

fig = go.Figure(data=go.Scatter(x=[1,2,3], y=[4,1,3]))
fig.update_layout(
    width=800,    # width in pixels
    height=400    # height in pixels
)
fig.show()
    

2. Specifying Size in Plotly Express

Plotly Express functions accept width and height arguments directly.

import plotly.express as px

df = px.data.iris()
fig = px.scatter(df, x="sepal_width", y="sepal_length",
                 width=900, height=500,
                 title="Iris Sepal Dimensions")
fig.show()
    

3. Setting Default Figure Dimensions via Template

Create a custom template with default layout.width and layout.height so you don’t need to specify size on every figure.

import plotly.io as pio

# Define template
pio.templates["my_size_template"] = pio.templates["plotly"].update({
    "layout": {
        "width": 700,
        "height": 350
    }
})
pio.templates.default = "my_size_template"

# Now all figures use the default size
import plotly.express as px
fig = px.line(px.data.gapminder(), x="year", y="lifeExp", color="country")
fig.show()
    

4. Configuring Exported HTML

When exporting to HTML or static images, you can specify size in write_html or write_image calls.

# Export to standalone HTML with fixed size
fig.write_html("chart.html", include_plotlyjs="cdn", full_html=True)

# Export to PNG with desired resolution
fig.write_image("chart.png", width=1200, height=600, scale=2)
    

5. Responsive and Container-Based Sizing

For web apps, you may want figures to fill their container’s dimensions. Use the autosize and responsive config options.

fig.update_layout(autosize=True)
fig.show(config=dict(responsive=True))
    

Comparison of Methods

Summary Checklist

1. Use fig.update_layout(width, height) for individual figures.
2. Pass width and height to Plotly Express functions.
3. Create a default-size template for consistent sizing.
4. Specify size when exporting HTML or images.
5. Enable autosize and responsive for dynamic layouts in web apps.