How to remove tracking metadata from my PDF

I have some good PDF ebooks I'm willing to share, but I suspect the seller embeds some tracking data in them to link them to my account, as every time I download them from the official website they have a different hash while being visually identical. The same when checking against the copies a friend bought from the same seller. Since I dont wanna get banned, can you recommend a way to remove that stuff?

19 comments

Could look into using exiftool, qpdf or pdftk, if you are comfortable with the terminal ✨

https://github.com/exiftool/exiftool

https://github.com/qpdf/qpdf

https://www.pdflabs.com/
- qpdf is very powerful. If OP is comfortable with the terminal, I'd recommend qpdf.
There's dangerzone by freedom of press
I would try reprinting the PDFs and comparing the hashes afterwards. That should remove any metadata in the headers as new headers are created.
- That wouldn't work for something like Pathfinder PDFs from the Paizo website. They add a text watermark with the name and email associated with your account on their site to each page of the document. It's not metadata, it's actual data
  
  Why would the checksum differ between downloads if there was a watermark with user identifiable data
Wow… The amount of information already being shared here is outstanding! Keep on rowing/patching mates
Maybe print the book via print to pdf and check again.
Okay hear me out... physically print the documents then, using a high resolution scanner, make a digital copy and finally use a raster to vector convertor.

I know this is probably dumb, but I just wanted to throw this out there.
- Why not just primt it to PDF. It doesn't lose any data, plus it doesn't take ages to scan the books.
If you're on Linux, Metadata Cleaner might work. https://flathub.org/apps/fr.romainvigier.MetadataCleaner
Exiftool can remove metadata. There might even be websites that can handle this.
Perhaps printing to pdf may work

19 comments