Private browser PDF editing

Password protect a PDF online for free.

Add an open password and optional reader permissions, then download an AES-256 encrypted copy created privately in your browser.

How to password protect a PDF online

1. Choose an unprotected PDF from your device.
2. Create and confirm a strong open password.
3. Optionally choose printing, copying, and editing permissions.
4. Protect and download the AES-256 encrypted copy.

Private browser-local PDF encryption

PDFMech loads the encryption engine and processes the document in a browser worker without uploading the PDF or password.

AES-256 open-password protection

The new PDF requires the password to open. Store it safely because PDFMech cannot receive or recover it.

PDF permission limits

Printing, copying, and editing restrictions depend on the PDF reader. A strong open password provides the meaningful protection.

Password protect a PDF online for free FAQ

Does PDFMech upload my PDF or password?

No. Inspection, encryption, verification, and download happen locally in your browser.

What encryption does PDFMech use?

The protected output uses AES-256 PDF encryption.

Can PDFMech recover a forgotten password?

No. PDFMech never receives or stores the password. Keep it in a trusted password manager or another safe place.

Can I protect an already encrypted PDF?

Not on this page. Remove the existing password first, then protect the unencrypted copy with a new password.