How to protect a PDF or ebook from being shared
Selling a PDF or EPUB means selling a file that can be copied in one click. Here are the realistic options, with their limits.
Passwords and DRM: effective but painful
A password gets shared along with the file. Heavy DRM locks out honest buyers (e-readers, printing, multiple devices) and creates support work.
Visible watermarks: a deterrent, but removable
A name in the footer deters some people, but it is easy to remove and gets in the way of reading.
Invisible watermark + limited links
Each buyer receives their own copy, marked with an invisible identifier in the PDF or EPUB metadata and text, through a link that expires and allows only a few downloads.
Result: a shared link runs out, and a circulating copy leads you back to its buyer.
Set it up in a few minutes
With Sentriqo, upload your PDF or EPUB, set the link lifetime and download limit, then connect your store (Shopify, Wix, Payhip, Gumroad, Lemon Squeezy, Etsy). Every sale is delivered automatically.