I had to add bleeds and enlarge an eight-page complex PDF. Traditional methods of working directly in Adobe or within InDesign were not feasible. I had to bring the PDF into Illustrator.

They involve what I think are very high-resolution JPEG images; there were many layers, various clipping masks etc. The original PDFs were huge: 1,250,000 kb!

I successfully worked in Illustrator to create the correct size, I then placed them in InDesign to ensure the correct size and the bleeds and get an eight-page PDF. Exporting to PDF took way too long and crashed InDesign. It may be even too big to work on our digital press.

Using the pre-flight option in Adobe crashed the Adobe PDF reader. Saving as a PDF to reduce file size in Adobe did not significantly reduce the file size.

What are my options? Is there some way to unilaterally flatten all the layers in Illustrator before I save it as a PDF to place or even just save it as a PDF that I can then combine to send to the digital press??

  • 3
    Using proper paragraphs and structure would make reading this much easier.
    – Scott
    Commented Jan 8, 2015 at 7:38
  • possible duplicate of How to reduce the size of a PDF with embed fonts (Calibri)
    – hsawires
    Commented Jan 8, 2015 at 15:31
  • 1
    There is a Flatten Transparency function under the Object menu. You can use it to simplify complex regions, or flatten the whole piece. However, it's difficult to suggest exactly what you might need.
    – Rsiel
    Commented Jan 8, 2015 at 16:07

6 Answers 6


The best compression technique I use for making PDF's smaller without loosing quality is saving it using the Adobe PDF Preset: PDF/X-1a:2001.

 Screeshot of the "Save Adobe PDF" Panel in Illustrator CS6

How it makes the file smaller is by defining a set of rules that forbid the use of certain PDF functions that are irrelevant for printing purposes and to enforce others that do improve its usefulness in prepress.

For more information you can read: http://kwikkopydc.com/tenley/2012/03/for-best-results-learn-how-to-create-pdfx-1a-files/

  • Somehow this preset doesn't allow sRGB profile or "No Conversion" option for color. So the file become bigger, actually. I use PDF icons in Xcode.
    – kelin
    Commented Sep 10, 2019 at 8:32
  • Fazaal Naufer's method (Save As: "PDF/X-1a:2001") is the easiest and highly effective. I was able to get my 30-page 640MB pdf down to just 20MB! Commented Dec 15, 2019 at 0:21
  • This just saved my butt for time. I went from 50MB files sizes to ~8MB total, just using the vanilla version of this setting with no tweaks. Commented Sep 30, 2020 at 18:33

This is a little cumbersome, but works for me sometimes. It should lower the file size and allow you to retain the ability to select/copy/paste text in PDF:

  1. Separate all text from image layers in AI file. Turn off text layers.
  2. Open document in PS to flatten and save each page to a separate PSD or JPEG file. Be sure to select Crop To: Bleed Box.
  3. Go back to AI and turn text layers on and image layers off. If there is lots of overlap or effects on text, you may need to place some on image layers.
  4. Place AI file (now only text) and PSD files into ID.
  5. Export ID as PDF. File size should be much lower.

If you aren't worried about the text being selectable, you can open the PDF directly in PS and eliminate the step of separating the text from the image layers in AI (being sure to Crop To: Bleed Box) for each page. Just place each flattened file into the INDD and then export to PDF.

  • That's a good workaround for this kind of situation if it fits. It seems likely that Saving As PDF from Illustrator will be more workable in this particular case. Commented Jan 9, 2015 at 1:17
  • Thanks for the comment. My understanding was that the PDF file size was too large when saving from AI or ID and that she was looking for a work around.
    – ispaany
    Commented Jan 14, 2015 at 21:52
  • You may be correct. It seemed to me from the description of the problem that she was placing the .ai files (normally the right thing to do) created from those huge PDFs, rather than creating new PDFs, which would be much smaller, and placing those in InDesign. Commented Jan 14, 2015 at 23:36

In my experience the large file size is due to Illustrator saving extra data help the file be easily editable when you re-open it. The most reliable method I have found for getting rid of this data is to save the file from Illustrator as a .eps or .pdf, and then open the file in a program call "Inkscape" (https://inkscape.org/en/download/). From Inkscape I re-save the file. The majority of the time this removes most of the extra data (I tried doing this to two example files on my computer and it turned a 30MB file into a 10MB file and a 2.60 MB file into a 0.29MB file). This method is not perfect and will not always reduce the file size to what I know the file size should be.

  • 1
    This may well be appropriate for some uses, but if you're having the PDF professionally printed, be aware that PDF's saved by Inkscape are always RGB, never CMYK.
    – HeyHeyJC
    Commented Nov 8, 2019 at 1:25

When you save your file from illustrator to pdf make sure unckheck illustrater editing capabilities, embed page thumbnails. Also check compression to downloadable sample to 150dpi.Make sure the pictures used are also to a minimal size (image size).

  • 1
    This appears to be for print, so compressing to 150 dpi would be a very bad idea. Commented Mar 21, 2018 at 9:02

I often export PDF files from Illustrator to use them as resizable vector icons in Xcode.

An iOS app should be as lightweight as possible, and PDFs are really hefty comparing to PNGs. For example, a simple monochrome 32x32 icon PNG usually takes no more than 1 KB, while the same PDF icon can easily take 200 KB! (I tried Fazaal Naufer's solution and got the 600 KB icon!)

I tried different options and through the long path of experience I came up with this profile:

Minimalistic (iOS).joboptions.

It's an Adobe PDF Preset, you can chose it when saving a file as a PDF, but first, you need to download the file and put it to the following folder:

~/Library/Application Support/Adobe/Adobe PDF/Settings

The idea behind this profile is to turn off all redundant functions. As the result you can get the icon taking only 40 KB. I believe, it can be improved further.


This may be pretty helpful!

I had a really large document just 2 pages but the file included a lot of clipping masks and transparencies.(at 25MB) What I do is rasterize the whole page and then save it as PDF/X-1a:2001. Because, I find that if you don't rasterize it, you will see the outline of your text boxes and if you place a png you may see the border around the image... just didn't feel comfortable with those this lines.. So after doing those steps, the file was down to 5000kb. Much better!!

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