How to reduce PDF file size on Mac OS X?

PDF files have great compatibility for operating systems and devices, so we’d love to share or archive files in PDF formats. But PDF can come bloated file sizes that can choke the email service or your website server. You may be interested in reducing PDF file size in many conditions. Follow this guide, you’ll learn how to reduce PDF file size with Compress PDF for Mac.

Video Tutorial for Compress PDF for Mac

Step 1: Launch Compress PDF app

Double click on the app icon in the Applications folder, you’ll see the following interface

compress pdf ui

Step 2: Add and compress PDF file

Drag and drop a PDF file to the file field, the compression will start instantly with the default preset option.


There are several preset compressing options. For different PDF files, you may need to choose the right option in order to reduce PDF file size efficiently.

pdf compression option

If the image in your PDF data has lower image scale or quality, but you choose an option with higher dpi and higher quality, you’ll get this error message. You should try another preset option. For example, if the default setting 96 dpi, medium quality can’t compress a PDF file, you should try lower dpi such as 72 or 50 with lower image quality. But if 50 dpi and low quality can’t compress a PDF file, the PDF file may be already compressed, or doesn’t contain any image elements within the original PDF file. Like all the other similar apps, even Adobe Acrobat can’t reduce PDF that was compressed before.

compress pdf error message

Step 3: Save the compressed PDF file

After compression, you can save the file to your computer, or send it via email as an attachment directly.

export compressed pdf