Fingerprint PDF Track Document Recipients

Embed an invisible fingerprint to identify which recipient leaked a confidential document. Free, no upload.

How to Fingerprint a PDF — Step by Step

PDF fingerprinting embeds a unique invisible watermark or identifier into a document copy so you can track the source of any leaked version. Each recipient gets a uniquely marked file.

1. Upload your PDF. Drop the file or click to browse.
2. Enter a fingerprint identifier (e.g. recipient name, email, or ID). This is the unique label embedded in each copy.
3. Click Fingerprint — a unique hidden marker is embedded. Processing happens entirely in your browser.
4. Download and send to the recipient. Repeat for each recipient with a different identifier. Each copy is uniquely traceable.

How does PDF fingerprinting work?

Doclair embeds the fingerprint by making subtle, invisible changes to the PDF's white space or character spacing. The changes are imperceptible to readers but detectable by analysis tools. This enables you to identify which copy was leaked if a confidential document is shared without permission.

Fingerprint PDF on iPhone and Android

Doclair works in mobile Safari and Chrome. Upload from Files and download each fingerprinted copy to send to individual recipients.

Frequently Asked Questions