Reduce PDF file size after exporting or when exporting from InDesign

Report · Dec 10, 2023

Hi Everyone,

It is my first time posting here.

I have searched the community for an answer to this and found a couple of posts, but I'm unable to downsize the file.

The report is about 120 pages and it has lots of linked ai files containing bar graphs and pie charts. All this files are about 1Mb to 1.5Mb. Is there a way to make these smaller? I'm guessing these are what make the "Content Streams" big. The report has a few photos, but not many and none are bigger than 1.5Mb.

The report Exports to about 82Mb when using "Smalles File Size" export features. If I open it in Acrobat Pro and save it as Reduced File Size, it doesn't reduce more dan a Mb here and there.

What can I do?

Also somethig curious... the fist time I saved a draft (before I added the photos to the cover and section covers) the report saved as a 25Mb PDF file. So I thought it was the photos, but I deleted all the photos to test it and it didn't make a difference.

Another thing I did was create stories so the proof-reader could work on the text in InCopy. I thought maybe this was what blew up my file, but I unliked all the stories, etc. and the PDF still exports big.

Report · Dec 10, 2023

You can only compress things so far, even for vector objects like your illustrator piecharts and graphs, the code needed to describe those objects has a limit. and, in fact, tend remain consistent in size no matter what PDF export ssertting you use. Since compression primarily targets image-based objects, where you have the opportunity to reduce resolution and save with higher compression. None of that affects vector code (unless you have use extendive placed/embedded images in those, of course). In reality, for 120 pages, 82MB is not unreasonable.

Your audit report shows the amount attributed to images, so they don't seem to be the issue. However, Content Streams contain all the ID-native text/objects along with all the postscript/PDF code from the AI files. If you want to source out if a particular placed file be the culprit(s), try make segmented PDFs. e.g save the first half as one PDF, and the remaining pages as another. Compare those sizes. If one is particularly larger than the other, split that one in half, etc etc. This will lead you to pages with "fat" objects on it. Also: if you have some complex graphics as Parent Page items, that could easily add up. But, if all these separate PDFs add up to about 82MB.

Failing all that, try save out as IDML and reopen that. this might chear out some clutter that is complicating in your file.

Report · Dec 13, 2023

Thanks Brad!
I will segment it and see how it goes.

Will post an update later today.

Thanks so much for your time 🙂

Report · Dec 17, 2023

Hi Brad, I was able to see what was causing all the Mb! it was actually not the graphs, but some maps that I had as PDFs.

This PDFs are somehow editable when I open them on Illustrator, but for some reason are always missing a bit of the map so I was not able to save them on Illustrator as non-editable PDFs. How can I do that on Acrobat PRO?

I've attached two images of the maps in Acrobat and in Illustrator with the missing bits. I don't know why this bits show missing when I open them in illustrator. This maps were created by my client on some kind of mapping platform.

Cheers 🙂

Report · Dec 18, 2023

This maps were created by my client on some kind of mapping platform.

The problem likely lies there. In short, PDF is an open standard and any software company is welcome to integrate features to create, edit, modify and export files in PDF format. Unfortunately, Adobe does not monitor or enforce any kind of compliance, so most third-party PDF tools have one set of flaws or another. (Mostly, the cheap or free Acrobat alternatives, or those that boast of having a small software footprint, or great speed, or some other "advantage" — and then below them are the readers built into most newer browsers, which emphasize speed and the ability to handle data in web-friendly ways over everything else.)

The other big class of PDF tools are those for the CAD and engineering world, meant to act as plugins to things like Revit and Solidworks. They are usually integrated with the ponderous version-control systems of those apps and designed to produce endless revision snapshots and the like. They tend to be just as bad at producing and managing actual PDF documents as are the cheap/free/web tools, because size, effciency and 'good code' aren't their priorities.

So if that map came from a CAD or GIS or other 'engineering' source... it's not surprising that it's bloated, fragile and acts strangely in the more standardized tools. The solution, if there is one, would be to get a fresh export with the system set to high compatibility or standardized output options, not the default used for internal/rev/snapshot purposes.

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Report · Dec 17, 2023

Hi Brad, I was able to see what was causing all the Mb! it was actually not the graphs, but some maps that I had as PDFs.

This PDFs are somehow editable when I open them on Illustrator, but for some reason are always missing a bit of the map so I was not able to save them on Illustrator as non-editable PDFs. How can I do that on Acrobat PRO?

I've attached two images of the maps in Acrobat and in Illustrator with the missing bits. I don't know why this bits show missing when I open them in illustrator. This maps were created by my client on some kind of mapping platform.

Cheers 🙂

Report · Dec 18, 2023

It all depends on what program created those PDFs to begin with. If they aren't Illustrator files (look at the PDF's document properties), then opening them IN Illustrator is not the best way. The fact they are already PDFs means they are already compressed as best as they could be; vector maps tend to have a lot of vector points and that increased complexity will quickly add up.

Report · Dec 19, 2023

Illustrator is not a universal pdf editor, as already pointed out.

Try opening the map pdf in Acrobat and save it as an optimized pdf using the settings shown in the screen shot below (File> Save as Other> Optimized pdf), then place it into InDesign and export to PDF/X-4 (not smallest file size*). You can select all of the "Discard & Clean up" optimizer options, unless there is something you specifically need, which may produce a much smaller pdf. The two suggested optimizer settings are also available as Acrobat preflight profiles. If this does not help, you can also export the map pdf to a high-res image from Acrobat and place that instead of the pdf, or use a preflight profile to convert the pdf content to an image.

*If the exported PDF/X-4 is still too big, optimize it in Acrobat to reduce the size.

Report · Dec 11, 2023

To reduce PDFs for preview, i use

https://www.ilovepdf.com/compress_pdf

Often better results than from Acrobat Pro (file size). Do not use for print things and for interactive forms (makes forms uneditable).