Other PDF Issues

Fix Adobe Acrobat Cannot Compress Imported PDFs Issue

Chanuka Geekiyanage Oct 19, 2026 869 views

Question details

Users are unable to significantly reduce the size of imported PDF files using standard compression tools.

Why Acrobat Can No Longer Compress Imported PDFs

Product: Adobe Acrobat
Device & OS: not provided
Scenario: Attempting to reduce the file size of an imported PDF document for easier sharing or storage.
Observed behavior: The Compress PDF or Optimized PDF tools produce little to no file size reduction when applied to the document.

Before you start

Ensure the PDF file is saved locally on your computer and check the document properties to verify it is not password-protected or restricted from editing.

Solution 1Recommended

Use Advanced PDF Optimization Settings

Manually adjusting the optimization settings allows you to strip out specific elements that bloat file size, such as embedded thumbnails and metadata.

Standard compression fails if the PDF contains objects that aren't targeted by basic algorithms. By using the 'Save as Other' feature, you can specifically target high-resolution images, embedded fonts, and unnecessary layers for removal.

Access Optimized PDF Tool

Open the document in Acrobat and navigate to 'File' > 'Save as Other' > 'Optimized PDF'.

Adjust Image Resolution

In the optimization menu, navigate to the Images panel and reduce the image resolution and quality settings for color, grayscale, and monochrome images.

Discard Unnecessary Objects

Go through the 'Discard Objects' and 'Discard User Data' panels to remove embedded thumbnails, file attachments, unused objects, and document metadata.

Save and Compare

Save the newly optimized file under a different name and check its file properties to compare its size with the original imported document.

Pre-compressed Files: If the PDF was already heavily optimized by another program before importing, Acrobat may not be able to reduce the size any further.

Solution 2

Process Scanned Documents with OCR

Scanned documents are essentially large image files. Converting these images into searchable text helps significantly reduce the file size.

Easily Compress PDFs with WPS Office

If your current PDF software struggles to compress complex documents, WPS Office provides a powerful, built-in PDF compressor that effectively reduces file size while maintaining excellent document quality.

1. Open the PDF File: Launch WPS Office and open the PDF document you want to compress.
2. Select the Compress Tool: Navigate to the 'Tools' tab on the top ribbon and click on the 'Compress' button.
3. Choose Compression Level: Select your desired compression level (HD, Standard, or Basic) based on your quality and size requirements, then click 'Compress' to save the reduced file.

High compression ratio with intelligent quality preservationFully compatible with Microsoft Office formats and Adobe PDF standardUser-friendly interface for one-click PDF compressionLightweight software that runs smoothly on low-spec devices

microsoft office alternative - wps office

Frequently Asked Questions

Can I compress a PDF that contains a digital signature?

Compression usually alters the internal structure of the document, which invalidates digital signatures. You will generally need to remove the signature or request an unsigned copy before you can significantly compress the file.

Why does my PDF size increase after trying to compress it?

If your original PDF was already highly compressed using a specific algorithm, running it through a standard optimization tool might embed new structural data, fonts, or use a less efficient compression method, resulting in a larger file.

Does removing metadata really help reduce PDF file size?

Yes, especially in documents that have been edited extensively over time or compiled from multiple sources. Hidden layers, editing history, and metadata can accumulate and add significant invisible bulk to your PDF.

PDF Troubleshooting