CheckThisFile
Tools for your documents

Protect confidential PDFs

Add a signed AI-use declaration and create an identifiable copy for each recipient.

Create confidential copies / Check a copy
Create confidential copies

or drop a PDF here

This name is printed as your own declaration. It is not an identity verification.

One per line, up to 10. Names are visible on their copies. Keep the recipient record private.

Declaration included in every copy

The issuer does not permit:

  • AI inference or automated AI analysis
  • Training AI models
  • Training generative AI models
  • Data mining

AI services may ignore these permissions. This does not guarantee that an AI will refuse the document.

PDF compatibility

A new sharing copy is created with a declaration page and a separate footer band. Narrow pages gain side margins. Original text and graphics are kept; links, bookmarks, interactive features and accessibility tags are not retained. Signed or protected PDFs are not rewritten.

Format and technical limits

PDF: 20 MiB, 100 pages and up to 10 recipients. Combined copies: 100 MiB. Recipient record: 256 KiB.

How to prepare and check confidential copies

  1. Select your PDF, enter the issuer and add recipients.
  2. Review the permissions and compatibility notes. Create the copies; each is signed and checked before download.
  3. Download each PDF and keep the private recipient record separately. Use Check a copy with that record to compare a returned file.
Does it stop an AI from reading the document?

AI services may ignore these permissions. This does not guarantee that an AI will refuse the document.

What is signed?

A C2PA credential binds the PDF bytes to its CAWG permissions and copy details. A key is generated in your browser for the batch, is not saved and does not verify a legal identity. This is not a qualified electronic signature and has no independent timestamp.

Can I identify a leak?

A matching record identifies the copy assigned to a recipient, not who actually disclosed it. Cropping, screenshots or re-export can remove identifiers and invalidate the signature. Keep your original record through an independent channel. A surviving visible code can be a clue even when the signature is no longer present.

What happens to my original PDF?

A new sharing copy is created with a declaration page and a separate footer band. Narrow pages gain side margins. Original text and graphics are kept; links, bookmarks, interactive features and accessibility tags are not retained. Signed or protected PDFs are not rewritten.

Is my data uploaded or saved?

Documents, recipients and signing keys are processed in your browser. They are not sent to the server or saved automatically. Required static components are downloaded; offline use is not guaranteed.

How long do the signatures last?

Self-issued certificates last one year and have no trusted timestamp. Later validation can report expiry. The record’s final fingerprints still allow exact-byte comparison without establishing a certified date.

Need to share a verification link?

Document registration is a separate workflow. Always register the final downloaded PDF after all marks and signatures have been applied.

Register a document