Create an unsearchable PDF document

[peterschneider]

Hello everyone

I want to create a PDF document that is unsearchable. I know that you can make it searchable with OCR software but still I want to create such a file.

I know how to create unsearchable PDF document by converting it into images but I want that the text can be marked and selected (visually) and when you paste it, you get only square symbols, points, or some other weird things. And yes you can still make such files searchable.

I will provide a link of a PDF file and I want to make the same.

google search

https://www.google.com/search?site=&source=hp&q=%22The+German+physicist+Roentgen%2C+while+studying+t...

I don't understand how google is still able to read the text but Adobe Acrobat not. Can someone explain it?

Currently I'm on Windows 10 with latest updates

and Adobe Acrobat Pro DC Version 2017.009.20058

And Using Latex to create PDF documents

Thank you very much

[Test Screen Name]

Probably Google does OCR.

[gkaiseril]

If you are using the Chrome browser then the Google PDF viewer can not extract the text but if you download it and open the download in Adobe PDF Reader you select text. You could also set security on the PDF to not allow copying, accessibility, and page extraction.

[peterschneider]

That is right. You can select it but when you try to paste the selected text, you get only points or squares. This is exactly what I want to achieve. I want to make the document difficult to edit. Also I want to avoid PDF password through security because there are many pages that can easily bypass the security of Adobe.

By the way

did the creator of the above PDF document decided to make the document unsearchable or was it just an error occurred during the export?

[Bernd Alheit · Accepted solution]

The document was created with Nitro Pro. May be a bug or feature of Nitro Pro.

[peterschneider]

Yes you are right.

Even I didn't manage to create unsearchable document using Nitro Pro, I managed to create one using Latex.

If anyone wants to know how, here is the link

https://tex.stackexchange.com/questions/11307/is-it-possible-to-produce-a-pdf-with-un-copyable-text

Although it doesn't look as good as the document in the first post, It is good enough for the start.

Anyway, thank you for your help.