Fingerprint a PDF to trace leaks
Generate per-recipient copies of a PDF with invisible identifying marks, so a leaked document can be traced back to whoever it was originally sent to. This tool is still in development — the page below explains what it will do and how it will handle your files.
Fingerprint PDF is in development
This page describes how the tool will work and how it will handle your files. It is not usable yet — the guide below is accurate about the intended behaviour.
How to Fingerprint PDF
- Open the tool. Go to the Fingerprint PDF page. There is nothing to install and no account to create.
- Add your file. Drag your PDF onto the drop zone or click to browse. The file is read directly by your browser and is not sent anywhere.
- Choose your options. Adjust the settings to match what you need. Sensible defaults are already selected, so you can usually skip this step.
- Download the result. Save the finished file. There is no watermark, no page limit, and no sign-up prompt.
How Fingerprint PDF handles your files
Fingerprint PDF runs entirely inside your browser tab using JavaScript and WebAssembly. Your file is never uploaded, which means it is never stored on a server, never queued for processing, and never visible to anyone but you.
In practice this matters most for documents you would hesitate to email: contracts, medical records, bank statements, identity documents and anything under an NDA. Because the work happens locally, using this tool carries the same disclosure risk as opening the file on your own computer — which is to say, none.
Frequently asked questions
Is Fingerprint PDF free?
Yes. Every tool on the site is free with no usage caps, no watermark on the output, and no account required.
Does Fingerprint PDF add a watermark?
No. Output files are clean. Watermarks are only ever added by the Add Watermark tool, and only because you asked it to.
Are my files uploaded to a server?
No. This tool processes files entirely in your browser, so they never leave your device. There is no server to upload to.
Do I need to install anything?
No. Everything runs in a normal web browser on Windows, macOS, Linux, Android and iOS.
When will fingerprint pdf be available?
This tool is in active development. The page is published so you can see exactly how it will work and how your files will be handled before it ships.
Is there a file size limit?
The practical limit is your device's available memory rather than a number we impose. Large files work on desktop; very large ones may struggle on older phones.