How to Compress PDF Files in Python

What Is IronPDF and Why Use It for PDF Compression?

IronPDF is a comprehensive Python PDF library that provides extensive PDF manipulation capabilities. Whether you're creating PDFs from scratch, manipulating, compressing, or reading PDFs, IronPDF offers the necessary tools. It provides an array of features to streamline your PDF workflows.

One key feature of IronPDF is its compression capability. It enables you to compress existing PDFs, effectively reducing file sizes while maintaining high PDF quality. This is particularly useful when dealing with large documents that require quick sharing over the internet or via email. The compression functionality works seamlessly with PDFs generated from various sources, including those created through HTML to PDF conversion.

IronPDF's compression algorithm intelligently optimizes images within PDF documents, which are often the primary contributors to large file sizes. By adjusting the image quality and resolution, you can achieve significant file size reductions while preserving document readability and visual integrity. This makes it an ideal solution for businesses that need to manage large volumes of PDF documents efficiently.

How Do I Install IronPDF in Python?

To install IronPDF using pip, simply use the following command:

 pip install ironpdf

After installation, you may need to configure your license key if you're using IronPDF in a production environment. The library offers a free trial period for development and testing purposes.

How Can I Compress PDF Files Using IronPDF?

The following Python code utilizes the IronPDF library to compress PDF documents effectively. This example demonstrates both basic compression and advanced compression with resolution scaling options.

from ironpdf import PdfDocument

# Load the PDF document from a file
pdf = PdfDocument("Image based PDF.pdf")

# Compress images in the PDF with a quality setting of 60 (out of 100)
# Lower numbers reduce quality to increase compression
pdf.CompressImages(60)
pdf.SaveAs("document_compressed.pdf")

# Compress images with an additional option to scale down image resolution according to their visible size in the PDF
# This may cause distortion depending on the image configurations
pdf.CompressImages(90, True)
pdf.SaveAs("Compressed.pdf")

from ironpdf import PdfDocument

# Load the PDF document from a file
pdf = PdfDocument("Image based PDF.pdf")

# Compress images in the PDF with a quality setting of 60 (out of 100)
# Lower numbers reduce quality to increase compression
pdf.CompressImages(60)
pdf.SaveAs("document_compressed.pdf")

# Compress images with an additional option to scale down image resolution according to their visible size in the PDF
# This may cause distortion depending on the image configurations
pdf.CompressImages(90, True)
pdf.SaveAs("Compressed.pdf")

from ironpdf import PdfDocument

# Load a PDF that may have been created from HTML
pdf = PdfDocument("large_report.pdf")

# Apply aggressive compression for maximum file size reduction
# Quality of 40 provides significant compression while maintaining readability
pdf.CompressImages(40)

# You can also compress after merging multiple PDFs
# This is useful when consolidating documents
pdf.SaveAs("highly_compressed.pdf")

# For PDFs with mixed content (images and text), consider:
# - Higher quality (70-80) for documents with important diagrams
# - Lower quality (30-50) for documents primarily containing photos
# - Medium quality (50-70) for general-purpose compression

from ironpdf import PdfDocument

# Load a PDF that may have been created from HTML
pdf = PdfDocument("large_report.pdf")

# Apply aggressive compression for maximum file size reduction
# Quality of 40 provides significant compression while maintaining readability
pdf.CompressImages(40)

# You can also compress after merging multiple PDFs
# This is useful when consolidating documents
pdf.SaveAs("highly_compressed.pdf")

# For PDFs with mixed content (images and text), consider:
# - Higher quality (70-80) for documents with important diagrams
# - Lower quality (30-50) for documents primarily containing photos
# - Medium quality (50-70) for general-purpose compression

Best Practices for PDF Compression

When working with PDF compression in Python, consider these best practices:

1. Test Different Quality Levels: Start with quality 70-80 and adjust based on requirements. Text documents can use lower quality without degradation.

2. Consider Your Use Case: For printing, use higher quality (80-95). For web or email, lower settings (50-70) suffice.

3. Batch Processing: Implement batch processing for multiple PDFs:

import os
from ironpdf import PdfDocument

def batch_compress_pdfs(input_folder, output_folder, quality=60):
    """
    Compress all PDF files in a folder

    Args:
        input_folder: Path to folder containing PDFs
        output_folder: Path to save compressed PDFs
        quality: Compression quality (1-100)
    """
    # Ensure output folder exists
    os.makedirs(output_folder, exist_ok=True)

    # Process each PDF file
    for filename in os.listdir(input_folder):
        if filename.endswith('.pdf'):
            input_path = os.path.join(input_folder, filename)
            output_path = os.path.join(output_folder, f"compressed_{filename}")

            try:
                # Load and compress the PDF
                pdf = PdfDocument(input_path)
                pdf.CompressImages(quality)
                pdf.SaveAs(output_path)
                print(f"Compressed: {filename}")
            except Exception as e:
                print(f"Error compressing {filename}: {e}")

import os
from ironpdf import PdfDocument

def batch_compress_pdfs(input_folder, output_folder, quality=60):
    """
    Compress all PDF files in a folder

    Args:
        input_folder: Path to folder containing PDFs
        output_folder: Path to save compressed PDFs
        quality: Compression quality (1-100)
    """
    # Ensure output folder exists
    os.makedirs(output_folder, exist_ok=True)

    # Process each PDF file
    for filename in os.listdir(input_folder):
        if filename.endswith('.pdf'):
            input_path = os.path.join(input_folder, filename)
            output_path = os.path.join(output_folder, f"compressed_{filename}")

            try:
                # Load and compress the PDF
                pdf = PdfDocument(input_path)
                pdf.CompressImages(quality)
                pdf.SaveAs(output_path)
                print(f"Compressed: {filename}")
            except Exception as e:
                print(f"Error compressing {filename}: {e}")

4. Monitor File Size vs. Quality: Review compressed output to ensure quality meets standards. Some images need higher settings.

5. Combine Optimization Techniques: Use compression with other features like merging PDFs before compression.

Why Should I Choose IronPDF for PDF Compression?

IronPDF provides reliable PDF compression capabilities for Python developers. It offers comprehensive features including page rotation, HTML to PDF conversion, and image manipulation. These combined capabilities make IronPDF an excellent choice for developers requiring complete PDF manipulation functionality.

Starting from $799, IronPDF provides developers with accessible licensing options, ensuring quality software at reasonable costs. With its robust PDF optimization functionality, IronPDF delivers efficient PDF compression capabilities for various applications.

The library's extensive documentation and code examples simplify implementing compression features in your Python applications. Whether you're building a document management system, optimizing PDFs for web delivery, or reducing storage costs, IronPDF provides the necessary tools for success.