How can I reduce the size of a PDF without flattening or removing editable form fields?

Forum|Forum|13 days ago
February 11, 2026
3 replies
214 views

The PDFs are generated automatically by our server and contain multiple editable form fields that must remain interactive.
We need to reduce the file size because the documents must be transmitted through an API gateway with a strict size limit.
Standard compression tools often flatten or remove the form fields, which is not acceptable.
We are looking for a way in Adobe Acrobat Pro 2015 to optimize/compress the PDF while fully preserving form fields, layout, and visual quality.

Dave Creamer of IDEAS

Community Expert

Update: I was able to inspect the PDF in question.

Embedded fonts were the main culprit causing the oversized document. For some reason, the fonts did not show up as un-embeddable under the Optimize PDF settings--however, they were listed under the Document Properties>Fonts. I suspect some form of corruption in the original program.

As mentioned before, “refrying” the PDF reduced the file size but when replacing the original pages, the form fields did not line up correctly. While this could be fixed by adjust the position of the fields per page, the document grew again upon saving.

I ended up using callas pdftoolbox to unembed all fonts. The Times New Roman changed to Minion Pro, which I believe is included in the newer versions of Acrobat. The file size, with form fields, ended up as 161K. (I inspected a couple of pages of the form but left the other pages for the OP to inspect.)

David Creamer: Community Expert (ACI and ACE 1995-2023)

Abhayy_4566

Participant

I think the reason is your entire font file is fully embedded.

open pdf File - save as other - optimized PDF

Now go to fonts tab now see subset embedded fonts when percent of characters used is less than, set this to 100%

Dave Creamer of IDEAS

Community Expert

When you click the Compress a PDF tool, select Advanced Optimization.

Click on Audit space usage in the upper-right corner of the dialog box.

See what’s taking up the bulk of space.

You can optimize the PDF without removing form fields (check all the options).

David Creamer: Community Expert (ACI and ACE 1995-2023)

MalokMalokAuthor

Participating Frequently

Hi Dave, thank you for your reply.

After checking the Audit Space Usage, we noticed that fonts account for 97.17% of the file size.
When we run the PDF optimization (keeping default settings and making sure not to select any form-related options), the file size is reduced by only about 1.5 MB, which is unfortunately not sufficient for our use case.

Attached you will find screenshots of the current Audit Space Usage and the Advanced Optimization → Fonts section.
If there is any recommended configuration or best practice to significantly reduce the space used by fonts, it would be extremely helpful.

Additionally, under the Tools section we noticed the JavaScript tool — could this be relevant or useful in this scenario?

We look forward to your feedback.
Thank you again for your support.

Bernd Alheit

Community Expert

@Bernd Alheit Which fonts do you use at the form fields?

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