I have a 17MB InDesign file. Not a huge file size for a 40 page booklet. When I convert it to a pdf it blows out to 70MB! Usually the file size is reduced when saved to a pdf. I can't figure this one out. I'm saving pdfs as I usually do and have never had trouble before. For proofing purposes I'm able to lower the file size in Acrobat, but I can't do this for the final print file as I need high res images. Any ideas as to why the file size is so large when I convert it?


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    Two people voted to close this question. I don't understand why people feel that they need to close proper questions with the claim that it's a: "Tech support question". How is this a tech support question about fixing a technology to work as advertised? How is this question / problem not related to design? I think it's a valid question, even if it is a simple one.
    – Joonas
    Commented Apr 29, 2015 at 11:46
  • You can lower your PDF file size by optmizing it in Acrobat Pro. Indesign and other software often leave data that are not always needed and add weight to your PDF. You could explore the option of resaving your file through Acrobat Pro, and see how the optmized version looks compared to your original layout. graphicdesign.stackexchange.com/questions/46153/…
    – go-junta
    Commented Jun 22, 2015 at 7:03

3 Answers 3


Press-ready PDF files are almost always much larger in terms of file size due to flattening and expanding of objects.

Note InDesign merely links to external images. However, a press-ready PDF must embed those links for proper reproduction.


Try the following to reduce size assuming you have acrobat and acrobat distiller.

1.) Crop the size of your booklet to the bleedbox. Bleedbox is simply trimbox + the allowed bleed which will be specified by the printer you are choosing for this booklet.

2.) Save the PDF as a post-script file. File --> Save As --> More Options Post-script

3.) Run this post-script file through Acrobat Distiller which will regenerate a fresh PDF. You can still select the settings for whichever standard you need the PDF to be generated at. X-1a 2001 is a pretty safe standard which most digital printers accept. This PDF might be smaller in size as it gets the PDF to bare bones and erases a lot of the information that InDesign adds into the file depending on the settings chosen upon exporting.

I guess this doesn't get to the brass tacks of the 'why' but assuming you need a smaller PDF that is still ready to send to the presses I hope this helps. :)

P.S. saving to postscript from adobe acrobat, also known as, refrying can have unintended consequences and it is important to closely inspect your files after refrying to make sure that nothing has gone wrong in the process. For more information on the risks of refrying you can consult this article here: http://www.prepressure.com/pdf/basics/refrying

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    Please don't suggest refrying (PDF -> PostScript -> PDF) as a generic way to reduce the size of PDF files. This process carries significant possibility to degrade PDF documents and should only used when you absolutely need to and know what you're doing. Commented Apr 29, 2015 at 9:51
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    For the purposes seemingly outlined in this situation (I can't be sure because details of her situation are sparse), my recommendation is really not that risky, assuming she chooses the right standards profile from the acrobat distiller that her printer requires. I also didn't really champion this as a generic or general use case, I was just trying to help this person out.
    – maxwell
    Commented Apr 29, 2015 at 15:26
  • Without having seen the file, the risk simply is too big, I'm sorry. There are all kinds of things that can go wrong while doing this: from bad transparency flattening, to font issues because fonts have to be translated to older formats to... you name it. And the problem is not with the conversion to PDF, the conversion from PostScript to PDF is relatively safe. It's the conversion from PDF to PostScript (over which you have close to zero control) that causes these issues. Don't put the idea in people's heads that this is a good plan. Commented Apr 29, 2015 at 20:03
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    Kate don't listen to this buzz kill, throw caution to the wind and let your PDF soar unweighted by its former InDesign MBs!
    – maxwell
    Commented Apr 30, 2015 at 17:09
  • All kidding aside though David, I feel like this article here gives a pretty balanced look at the pros and cons of my advice, i.e. 'refrying' - prepressure.com/pdf/basics/refrying - and so, taking your comments to heart, I append this to my answer as a polite hedge.
    – maxwell
    Commented Apr 30, 2015 at 17:19

There is no way to gess here what is that you have and what is the configuration or usage you need.

I don't think "convert" is a proper word for generating a pdf. Here is why.

PDF is not a "working" file, it is an output file. And there is not one "flavor" of pdf but can be customized according to your target needs.

Among the things you can configure your file that affects the file size are:

1) Color mode for images. If you used RGB files and you need a press ready file will be converted to CMYK. This files are bigger.

2) Resampling of the images. If the images used are bigger than ppi you need. This actualy can reduce a little the output file.

3) Compression. Indesign file size does not take into acount the external images. And thoose images can be a verey compressed jpg photos for example. On the output pdf they are inside and re-compressed as needed. But you should NOT use jpg compression on the press quality. The recomended compression is none or ZIP, which compresses less than the original jpg.

4) Converting text to curves. Instead of having text, you have thousands of curves which ocupies more space.

I'm adding another thing here.

If you are preparing a file for print file size does not matter.

If you need to send the file for email, play with thoose options.

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