WebP to PNG Conversion Using Python

In this comprehensive guide article, we'll discuss in detail how to convert WebP images to PNG format using Python code.


WebP and PNG are both well-known image formats. Each of them has its own benefits and use issues. WebP image format is basically known for its high compression and performance. It is commonly used on the website to reduce page load times. But there are still some situations where you may want to convert a WebP image to a more widely supported PNG format, such as when working with legacy systems or applications that do not support WebP.

In this comprehensive guide article, we'll discuss in detail how to convert WebP images to PNG format using Python code. We will use the pillow library (PIL). It is a powerful Python image library that allows users to easily manipulate and edit different image formats. Whether you're a beginner or an experienced developer. This step-by-step guide will explain the complete conversion process.

Setting Up the Environment

Before we dive into the transformation process itself, let's make sure we have the necessary
tools and libraries.

Installing Required Libraries:

Before we start writing code, we need to install the pillow library. Pillow is basically a fork of
the original PIL library and provides powerful image-processing capabilities for Python. You can
install the pillow using Pip commands. Open a terminal or command prompt and run the
following command to install the Pillow library in your project.:

!pip install Pillow

Load a WebP Image

Once Pillow is installed, You can start loading a WebP image for the conversion process.

from PIL import Image # Open a WebP image
webp_image Image.open("input.webp")

In this code, First, we import the Image class from the Pillow library and use the Image.open()
method to load a WebP image named input.webp.

Converting to PNG

Now that we've Loaded the WebP image, it's time to convert it to PNG format.

png_image = webp_image.convert("RGBA")

In this code example, we converted the WebP image (webp_image) that you uploaded to PNG
image format and stored it in variable png_image. The RGBA mode specifies that the image
should have red, green, blue, and alpha channels.

Saving the PNG Image


In this piece of code, we used the "save()" method to save the PNG image with the name of
"output.png". You can specify any file path and name according to your needs.

Error Handling

While the conversion process is relatively straightforward. It is important to consider the
potential issues that may arise while running code.

    png_image = webp_image.convert("RGBA")
except Exception as e:
    print(f"An error occurred: {e}")

By wrapping the conversion process and storing code inside the try-except block. we can handle
any exceptions that arise during the whole process perfectly. This can ensure that our script will
not crash if something goes wrong during the process.

Bulk Image Conversion:

The above code is perfect for Converting a single image. But what if you have a lot of WebP images
that you want to convert to PNG? Below Python code makes bulk processing straightforward.

from PIL import Image
import os

webp_dir = "webp_images"
png_dir = "png_images"
os.makedirs(png_dir, exist_ok=True)

for filename in os.listdir(webp_dir):
    if filename.endswith(".webp"):
        webp_image = Image.open(os.path.join(webp_dir, filename))
        png_image = webp_image.convert("RGBA")
        png_image.save(os.path.join(png_dir, filename.replace(".webp", ".png")))

In the above code, we define the input and output directories, we loop for WebP images in the input directory and call the conversion process and save process for each image. The Converted PNG files are stored in a specified source directory with the same file name.

Performance Considerations

With a large number of image conversions, performance becomes an issue. Here are some tips to improve your conversion process:
  • Use multiprocessing: If you have a multi-core processor, you can accelerate large-scale conversions by using Python's multiprocessor library to work in parallel.
  • Resize images: If you have large-size images consider resizing your images to reduce their size. This can reduce processing time and also can save disk space.

Testing and Validation

After the transformation process, it's important to test and validate the converted PNG images to ensure these resulting images meet your quality standards. You can use any available image viewing tools or create automated tests to check dimensions, color accuracy, and transparency.

Advantages of Converting WebP to PNG

Compatibility: PNG is the most supported image format and almost all web browsers, operating systems, and image editing software can display and work with PNG files without facing any issues. Converting your WebP to PNG ensures compatibility with older systems or software that may not support WebP.
Lossless Compression: PNG uses lossless image compressions. That means the quality of your image is preserved during conversion. This is important for situations where image quality is required such as in graphic design..
Transparency Support: PNG supports transparency that’s ideal for images that require a transparent background. This format is commonly useful for logo designs and icon designs.

Disadvantages of Converting WebP to PNG:

File Size: PNG files are larger in size than WebP files, especially for photographic images. If website performance and page load times are concerned, then it’s not good to use large-size PNG files.
Limited Compression: PNG uses few compression methods which is less effective at reducing file size than high-compressive WebP files. 

Additional Resources
Pillow (PIL Fork) Documentation - You can use official documentation for the Pillow Library.
Python Multiprocessing Documentation - For parallelizing tasks use this link to learn more about parallelizing tasks with the multiprocessing library.


Converting WebP images to PNG format is really simple in Python. Especially if you are dealing with systems that require PNG compatibility. The pillow library makes this conversion task easier by making it accessible to developers of all levels. With the knowledge gained from our article guide, you can confidently handle WebP to PNG conversions and integrate them into your projects.