FAQ | Frequently Asked Questions

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Q: How can I reduce the size of my PDF file?
A: Here's the background and solution:

My paper was published online and when I downloaded it from the web I realized the PDF file is 43.7 MB! So it's too big to e-mail to anyone. I’m concerned that some folks in places with slower servers may not even be able to download it.

See also: A Note About Download Speeds below

Q: So, how can I reduce the size of my PDF file?
A: Depending on how the pdf file was constructed, you may be able to reduce the overall size; but it will involve reducing the quality of the photos and images.
  1. Open the pdf file in Adobe Acrobat Pro.

  2. In the menu bar select AdvancedPDF Optimizer…
    Acrobat Advanced menu screenshot
    Here is a screenshot of the default PDF Optimizer window:
    screenshot of the default pdf optimizer window
  3. The first thing you can do to try and reduce the pdf size is to make the pdf file compatible with the more recent versions of Acrobat - either version 8 or 9 (doing this will not affect the quality of the pdf images). The more recent the version, the smaller the pdf may be. It may be the pdf is already set to be compatible with the most recent version of Acrobat.
  4. The second thing you can try involves reducing the quality of the images in the pdf file.

    NOTE: Before you begin adjusting the ppi and compression settings, select the box at the bottom that says, “Optimize images only if there is a reduction in size”.

    The settings in the screen shot above are the standard ones. Keep in mind that print quality for photos is 300 ppi; most screen resolution is 72 ppi. So if you want people to be able to print good quality images, you don't want to drop the resolution too low. I would suggest using the default compression settings (150 for above 225 ppi with medium jpg compression) as a starting point to see if it reduces the pdf file size.

Typically PDF files already incorporate compression, so further attmpts at compression by using ZIP-ing the PDF file would be of little use.

A Note About Download Speeds

You can check the estimated download speed for files of various sizes and using different connection speeds here: http://www.onlineconversion.com/downloadspeed.htm

By the way, the download burden of your original PDF is about the same as downloading three songe, Summertime, My Man’s Gone Now, and It Ain’t Necessarily So on The Modern Jazz Quartet Plays George Gershwin’s Porgy and Bess CD from iTunes.