How to flatten pdf?

I am trying flatten a pdf? That is make it so that only information contained in the pdf file is that which is visible.

Note I’m not trying to redact a document. However, this issue may in some manner be relevant to redacting as well. I effectively want the flattened pdf to be as if one printed and scanned the document, yet retains the full resolution of the source.

I have documents which are produced in Pages and consist in multiple layers. It might be something like a background image or form on which I drop commentary, another image, or other information. Most of the time this layering is not visible in Peview. Although if you try to select portions of the document Preview might typically let you highlight the built up components of the page.

However, I have noticed that when displaying in Adobe Acrobat, you frequently get to momentarily see what should in effect not be visible. I have tried the version of pdfPen which comes with Setapp but that did not seem to have flattening in the sense which I need. I believe that exporting the pdf from Preview to a tiff or png would eliminate the layering since that is effectively scanning the document. However, this would either reduce the resolution or result in a very bloated files when converted back to pdf.

Does anyone know of the proper way to achieve the type of flattening I would like?

Look at PDF expert for Mac. It has an option to save a pdf as a flattened pdf.


@rkv - I have successfully used two methods:

  1. “Export as PDF” function from the Preview app. This will flatten any annotations done within the Preview app, and presumably will flatten annotation layers from other apps.
  2. as @RobA suggested, PDF Expert works well. "Save as Flatten is in the “File” drop-down commands.

I’m not sure that I understand the comments in your third paragraph regarding Pages and Preview. Are you trying to view the Pages file directly Preview, or to view an annotated PDF file that was created from a Pages file?


Yes, I also use “Export as PDF” in Preview. You should always be able to Print… and then select “PDF” to do this from any application. Also, PDFPenPro has an export flattened PDF in the menu tree.

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I go trough the print menu and then save as PDF again.

Hello all,

I am not having much luck with things at the moment – and would really appreciate some help.

We are releasing a cover-letter that will be a PDF-attachment to an email, requesting people to complete a survey.
The letter is signed off by 4 persons.

I have tried the (1.) Cmd+P >> save as; (2.) Export as PDF from Preview; and (3.) Flatten Document from PDF Expert – with no change.
The signatures can still be selected, copied, and pasted as a “dropped image” into Word. Granted, when dragging it again from Word and out, then the 2nd paste results in nothing – but people would still be able to copy/paste at the first go…

This has never happened before, since options (1.) or (2) always worked before.

I still have PDFPenPro – but not sure what it might offer, that I can try?
Any suggestions??

You can add a password to the document and then protect against copying data. However the passwords can be easily broken (at least they used to be) and it’s always possible to use a screen capture utility to get the signatures.

Thanks – password is unfortunately not feasible, since it might put people off from actually reading the attachment.
And once entered, the cut/paste option still exists.

In the end, I left it as is, since your point is valid on the various screen-capture utilities in any event allowing for this (which I how we created the letter in the first place!).

Still strikes me as odd that I couldn’t flatten it – but oh well.

It’s an owner password which doesn’t necessarily prevent reading it but restricts various selectable permissions. Adobe Acrobat and PDF Pen handle it. Preview doesn’t. Not sure about others. But as said, it’s not much of a protection.

Lots of free-to-$30 PDF-unlock apps out there. I keep running into sales sites featuring Cisdem/Wondershare but there are others. A decade ago I bought one for $10 to unlock a pdf I’d accidentally locked somehow with a password I’d forgotten, and running the app overnight got the password. Maybe the protection features have improved over the years, but I’d guess the pdf-cracking apps have as well.

I did not know this. Many thanks - something to keep in mind for the future!

Seems to have kept pace. I created a small PDF, locked it, and uploaded to a website that removes passwords for free. Took it under a second (seemed instantaneous!).

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I do a slight variation of the “Print” method. I select “Print” then “Open in Preview” in the PDF menu. This opens a new document in Preview. I do this to make sure the document is flattened.

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Yes, this is a good way to flatten the document while confirming the appearance while the Preview window is displayed.

There can be a slight difference between “Print > Open in Preview” and “Export as PDF”. Sometimes the margins of the document are not handled correctly when using “Print > Open in Preview”, and text near the document’s margins will be cut off. “Export as PDF”, if this choice is available, seems to handle the margins better and does not cut off text at the periphery of the document. Of course, the Preview window is not displayed, so you must open the document after saving it to check the result.