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How to Compress PDFs

Learn how to reduce PDF file size while keeping your document practical to view, share, print, and store.

Updated 13 September 20265 min read
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Introduction

PDF files can become large when they contain high resolution images, scanned pages, embedded fonts, or other detailed content. Large files can take longer to upload, download, share, and store.

Compressing a PDF reduces its file size so the document is easier to handle while keeping the content useful and readable. The amount of reduction depends on the content and structure of the original PDF.

In this guide, you will learn how to compress PDF files using the FlagsDev PDF Compress tool.

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PDF compression workflow showing a large PDF being reduced to a smaller file
Select your PDF, process the document, and save a smaller version of the file.

What is PDF compression?

PDF compression is the process of reducing the amount of data required to store a PDF document. Depending on the PDF, compression can reduce image data, remove unnecessary information, or optimize how content is stored.

For example, imagine you have a PDF that is 18 MB because it contains several high-resolution scanned pages. Compressing the document may produce a smaller version that is easier to upload or send.

The final file size depends on the original document. A PDF containing mostly text may not become significantly smaller, while a PDF containing many large images or scans may have more opportunities for size reduction.

Original

Large PDF

Process

Compression

Result

Smaller PDF

How to compress PDFs

Follow these steps to reduce the size of your PDF document.

1

Open the Compress PDF tool

Open the Compress PDF tool.

The tool provides an interface where you can select the PDF you want to optimize.

2

Select your PDF file

Select the PDF document you want to compress from your device.

Choose the original document rather than an already compressed copy when possible.

3

Start the compression

Start the compression process after selecting your PDF.

The tool processes the document and attempts to reduce its file size.

4

Review the result

Once compression has finished, review the resulting document and check that the content is still suitable for your intended use.

Compression results can vary depending on the original PDF. Documents containing mostly text may have limited size reduction.

5

Download the compressed PDF

Save the compressed PDF directly to your device.

You can now use the smaller file for sharing, uploading, storing, or other supported purposes.

Check the result after compression

Always open the compressed PDF and verify that the pages, text, images, and overall document quality are suitable for your needs before replacing the original file.

Tips for compressing PDFs

  • Keep the original PDF until you have verified the compressed version.
  • Image-heavy and scanned PDFs may have more potential for size reduction than text-only documents.
  • Check the compressed document before submitting it to a website or sending it to someone else.
  • If a website has a maximum upload size, compare the final file size with that limit before uploading.
  • Avoid repeatedly compressing the same PDF when unnecessary, especially when the document contains images.

Privacy

Browser based processing

FlagsDev is designed around browser based file processing where supported by the individual tool. This approach can help reduce unnecessary file transfers because supported operations can be performed directly in your browser.

For the most accurate information about how data is handled, review the FlagsDev Privacy Policy.

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Reduce your PDF file size and create a more manageable document with the FlagsDev Compress PDF tool.

Open Compress PDF Tool