How to use Protect PDF: a step-by-step guide
Add a password and restrict printing or copying with AES-256 encryption.
Open the free tool, follow the steps and download your result. No sign-up required.
Before you start
- One PDF within the free-plan size limit.
- A password of at least four characters; a longer passphrase is safer.
- A decision about whether recipients may print or copy content.
Step by step
- Upload the PDF you want to protect.
- Enter a password of at least 4 characters and set the permissions.
- Download the encrypted PDF — it will ask for the password when opened.
Common mistakes
- Using a short or reused password for a confidential document.
- Forgetting that a user password can be shared or screenshotted; encryption is not a substitute for access control.
After you download
Download the protected PDF, open it in a PDF viewer and test the password. Keep an unprotected original in a safe place in case the password is lost.
Questions and answers
What encryption is used?
AES-256 (PDF 2.0, revision 6). It is the strongest option still recommended and works in modern readers and browsers.
I lost the password — can it be recovered?
No. The password is never stored, and AES-256 cannot be brute-forced in practice.
Why is printing blocked by default?
Restricting printing is the usual reason to protect a document. Tick “Allow printing” if you want it enabled.
Related guides
Unlock PDF
This guide removes a password you already know by rebuilding the document as a new, unencrypted PDF. It cannot recover or guess a password you do not have.
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This guide explains what the compressor can and cannot shrink. The tool repacks the PDF and removes hidden metadata without lowering image quality, so text-heavy files usually benefit most.
Read the step-by-step guide →