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November 23, 2025
Question

How to Optimize Large PDF Files Without Losing Quality?

  • November 23, 2025
  • 1 reply
  • 566 views

Hi everyone,
I often work with large PDF files (50MB+), and I need to reduce their size for easier sharing via email and cloud storage. I’ve tried using Adobe Acrobat’s “Reduce File Size” feature, but the quality sometimes drops noticeably, especially for images.

I came across some tips on optimizing PDFs at OnStreams, but I’m not sure which method is best for maintaining image and text quality.

Is there a recommended workflow or settings in Acrobat that help optimize PDF files while keeping quality high?
Are there differences between using Save As Optimized PDF vs Reduce File Size, and when should I use each?

Any tips or best practices would be really helpful. Thanks in advance!

1 reply

JR Boulay
Community Expert
Community Expert
November 23, 2025

1. "Reduce File Size" is the same thing than "Save as Optimized PDF" with the "Standard" (default) setting.

 

2. Optimising a file always involves a compromise between quality and file size.
There is no magic setting, but you should know that it is better to increase the JPEG (or JPEG2000) compression rate than to decrease the resolution of the images. This gives better results.

Acrobate du PDF, InDesigner et Photoshopographe