Protect PDF vs Flatten PDF

Use /pdf-tools/flatten-pdf when you only need to convert interactive form fields into static content so the document is easier to share, archive, or print.

Use /pdf-tools/protect-pdf when the PDF should require a password before opening, or when you want to restrict printing, copying, or editing in the encrypted copy.

Flattening alone focuses on making form fields static. /pdf-tools/protect-pdf encrypts the PDF with a password, creates an owner password internally, and writes permission settings into the protected file.

That difference matters when the main risk is unauthorized opening or casual redistribution. If you only need stable field values, flattening is often enough. If access should be password-gated, protection is the better fit.

Neither workflow replaces certificate-backed digital signatures, full e-signature audit trails, or enterprise document management controls.

If you need legal signing status, identity verification, or policy enforcement across an organization, use a dedicated document platform after preparing the PDF.

A common send-ready sequence is sign with /pdf-tools/sign-pdf, flatten completed form fields with /pdf-tools/flatten-pdf if needed, compress with /pdf-tools/compress-pdf if file size matters, then finish by locking the final PDF with /pdf-tools/protect-pdf.

If you want the broader context for email delivery, continue to /guides/how-to-prepare-pdf-for-email-delivery after choosing the right finalization step.