How to Convert SVG to PNG in Python

7 min readJan 30, 2024

SVG (Scalable Vector Graphics) is a popular format for creating and displaying vector images on the web. SVG files are XML-based and can be edited with any text editor. They are also scalable, meaning they can be resized without losing quality.

However, sometimes you may need to convert your SVG files to PNG (Portable Network Graphics) format, which is a raster image format that supports lossless compression and transparency. PNG files are more widely supported by browsers and applications, and they can be easier to manipulate with image processing libraries.

In this blog post, I will show you how to convert SVG to PNG in Python using four different methods:

Using CairoSVG, a Python library that wraps the Cairo 2D graphics library
Using svglib, a Python library that converts SVG files to ReportLab Drawing objects
Using rsvg, a Python binding for the librsvg library
Using ImageMagick, a command-line tool for image manipulation

I will also compare the pros and cons of each method, and provide some tips and tricks for optimizing your conversions. Let’s get started!

Method 1: Using CairoSVG

CairoSVG is a Python library that allows you to convert SVG files to PDF and PNG using the Cairo 2D graphics library. You can install it with pip, use it as a standalone command-line program, or as a Python library with the svg2png function¹.

Here is an example of how to use CairoSVG in Python:

# Import CairoSVG
import cairosvg

# Convert SVG file to PNG file
cairosvg.svg2png(url="input.svg", write_to="output.png")

The url parameter can be a file path, a file object, or a URL. The write_to parameter can be a file path or a file object. You can also specify other parameters such as width, height, scale, dpi, parent_width, parent_height, and output_width to control the output size and resolution¹.

CairoSVG is a simple and fast way to convert SVG to PNG in Python, but it has some limitations:

It does not support all SVG features, such as filters, masks, and animations¹
It may produce inaccurate results for some SVG files, such as missing elements, wrong colors, or distorted shapes²
It requires the Cairo library to be installed on your system, which may not be available on some platforms¹

Method 2: Using svglib

svglib is a Python library that converts SVG files to ReportLab Drawing objects, which can then be rendered to various formats, such as PDF, PNG, or EPS. You can install it with pip, and use it with the svg2rlg function³.

Here is an example of how to use svglib in Python:

# Import svglib and reportlab
from svglib.svglib import svg2rlg
from reportlab.graphics import renderPM

# Convert SVG file to ReportLab Drawing object
drawing = svg2rlg("input.svg")# Convert ReportLab Drawing object to PNG file
renderPM.drawToFile(drawing, "output.png", fmt="PNG")

The svg2rlg function takes a file path, a file object, or a URL as input, and returns a ReportLab Drawing object. The renderPM module provides functions to render ReportLab Drawing objects to various formats, such as drawToFile, drawToPIL, or drawToString³. You can also specify parameters such as dpi, bg, or transparent to control the output quality and appearance⁴.

svglib is a versatile and powerful way to convert SVG to PNG in Python, but it also has some drawbacks:

It does not support all SVG features, such as gradients, patterns, markers, and clipping paths³
It may produce incorrect results for some SVG files, such as wrong fonts, missing text, or overlapping elements²
It requires the ReportLab library to be installed on your system, which may not be compatible with some licenses³

Method 3: Using rsvg

rsvg is a Python binding for the librsvg library, which is a C library for rendering SVG files. You can install it with pip, and use it with the rsvg module.

Here is an example of how to use rsvg in Python:

# Import rsvg and cairo
import rsvg
import cairo

# Load SVG file as rsvg handle
handle = rsvg.Handle("input.svg")# Get SVG dimensions
width = handle.get_property("width")
height = handle.get_property("height")# Create cairo surface and context
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
context = cairo.Context(surface)# Render SVG to cairo surface
handle.render_cairo(context)# Save cairo surface to PNG file
surface.write_to_png("output.png")

The rsvg.Handle class takes a file path, a file object, or a data buffer as input, and returns an object that represents the SVG file. You can use the get_property method to get the SVG attributes, such as width, height, title, or desc. You can also use the set_dpi method to set the dots per inch for the rendering.

The render_cairo method takes a cairo context as input, and renders the SVG file to the cairo surface associated with the context. You can use the cairo library to create and manipulate cairo surfaces and contexts, and save them to various formats, such as PNG, PDF, or SVG.

rsvg is a reliable and accurate way to convert SVG to PNG in Python, but it also has some limitations:

It does not support all SVG features, such as animations, filters, and masks
It may produce unexpected results for some SVG files, such as blurry images, wrong sizes, or missing elements²
It requires the librsvg and cairo libraries to be installed on your system, which may not be easy on some platforms

Method 4: Using ImageMagick

ImageMagick is a command-line tool for image manipulation, which supports over 200 image formats, including SVG and PNG. You can install it from its official website, and use it with the convert command.

Here is an example of how to use ImageMagick in Python:

# Import subprocess
import subprocess

# Convert SVG file to PNG file using ImageMagick
subprocess.run(["convert", "input.svg", "output.png"])

The convert command takes an input file and an output file as arguments, and converts the input file to the output file format. You can also specify other options, such as -resize, -quality, or -background to control the output size, quality, and appearance.

ImageMagick is a fast and easy way to convert SVG to PNG in Python, but it also has some disadvantages:

It does not support all SVG features, such as fonts, text, and gradients
It may produce poor results for some SVG files, such as pixelated images, wrong colors, or distorted shapes²
It requires the ImageMagick tool to be installed on your system, which may not be secure or convenient

Conclusion

In this blog post, I have shown you how to convert SVG to PNG in Python using four different methods: CairoSVG, svglib, rsvg, and ImageMagick. Each method has its own advantages and disadvantages, and you may need to choose the one that suits your needs and preferences.

Here is a summary table of the four methods:

Method Pros Cons CairoSVG Simple and fast Does not support all SVG features, may produce inaccurate results, requires Cairo library svglib Versatile and powerful Does not support all SVG features, may produce incorrect results, requires ReportLab library rsvg Reliable and accurate Does not support all SVG features, may produce unexpected results, requires librsvg and cairo libraries ImageMagick Fast and easy Does not support all SVG features, may produce poor results, requires ImageMagick tool

I hope you have learned something new and useful from this blog post. If you have any questions, comments, or feedback, please feel free to leave them below. Thank you for reading!

FAQs

What is SVG?

SVG stands for Scalable Vector Graphics, which is a format for creating and displaying vector images on the web. SVG files are XML-based and can be edited with any text editor. They are also scalable, meaning they can be resized without losing quality.

What is PNG?

PNG stands for Portable Network Graphics, which is a format for storing and displaying raster images on the web. PNG files support lossless compression and transparency, and are more widely supported by browsers and applications than SVG files.

Why convert SVG to PNG?

There are several reasons why you may want to convert your SVG files to PNG files, such as:

To make your images more compatible with different browsers and applications
To make your images easier to manipulate with image processing libraries
To reduce the file size and bandwidth of your images

How to optimize your SVG to PNG conversions

Now that you know how to convert SVG to PNG in Python, you may want to optimize your conversions to get the best results possible. Here are some tips and tricks to help you with that:

Choose the right method for your use case. Depending on your needs and preferences, you may want to use different methods for different situations. For example, if you need a simple and fast conversion, you may use CairoSVG. If you need a versatile and powerful conversion, you may use svglib. If you need a reliable and accurate conversion, you may use rsvg. If you need a fast and easy conversion, you may use ImageMagick.
Experiment with different parameters and options. Each method has its own parameters and options that you can use to control the output size, quality, and appearance. For example, you can use width, height, scale, dpi, parent_width, parent_height, and output_width with CairoSVG. You can use dpi, bg, and transparent with svglib. You can use set_dpi with rsvg. You can use -resize, -quality, and -background with ImageMagick. You may need to try different values and combinations to find the optimal ones for your conversions.
Validate and optimize your SVG files. Before converting your SVG files to PNG files, you may want to validate and optimize them to make sure they are well-formed and efficient. You can use online tools, such as SVG Validator or SVGOMG, to check and improve your SVG files. You can also use Python libraries, such as svgwrite or svgutils, to create and manipulate SVG files programmatically.
Compare and evaluate your conversions. After converting your SVG files to PNG files, you may want to compare and evaluate them to see how they look and perform. You can use online tools, such as ImageDiff or ImageMagick Compare, to compare and measure the differences between your SVG and PNG files. You can also use Python libraries, such as Pillow or OpenCV, to load and display your PNG files, and calculate metrics, such as PSNR or SSIM, to quantify the quality of your conversions.

By following these tips and tricks, you can optimize your SVG to PNG conversions in Python, and get the best results possible. I hope you find them useful and helpful. If you have any questions, comments, or feedback, please feel free to leave them below. Thank you for reading!