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Security

Password protect a PDFwith AES-256 encryption

Lock a PDF with a password so only the people you share it with can open it.

  • Free during beta
  • No sign-up
  • 25 MB per file

Guest session. Files automatically expire after 60 minutes.

In short

EnDocs AI encrypts a PDF with AES-256 and the password you choose, so the file cannot be opened without it. Printing, copying and annotating remain allowed once it is opened.

Last updated

What it is

What is Protect PDF?

Password protection encrypts the contents of a PDF. Without the password, viewers show a prompt and the text, images and pages cannot be read.

It lets you send a contract, payslip or statement by email knowing that a forwarded or lost copy cannot be read without the password.

Try saying

“Protect this PDF with the password "Blue-Harbour-42".”

How to use it

Protect PDF in 3 steps

  1. 1

    Upload your PDF

    Drop your file in the box above or choose it from your device. No account is needed.

  2. 2

    Set a password

    Say "protect this with the password …". Choose something you can share separately and remember.

  3. 3

    Download the result

    Your encrypted PDF is ready. Download it, or keep working on it in the same workspace.

Behind the scenes

How your file is processed

  1. 01

    AES-256 encryption

    The file is encrypted with AES-256, a strong standard encryption used for sensitive documents.

  2. 02

    Open password and owner password

    The password you give is required to open the file. A separate owner password can be set; if you do not, the same password is used.

  3. 03

    Permissions after opening

    Once opened, the document can be printed, copied and annotated.

  4. 04

    Already protected files

    If the PDF is already locked, you are asked for its current password before it can be re-protected.

Your file stays yours

60 min

Files are deleted automatically about 60 minutes after upload, when your guest session ends.

[PERSON_1]

Names, numbers, emails and addresses are swapped for placeholders before text reaches an AI model, then restored in the reply.

0 accounts

No account is created. Your guest session is the only thing that identifies your files.

At a glance

Protect PDF facts

Input
One PDF
Output
One encrypted PDF
Encryption
AES-256
File size
Up to 25 MB per PDF
Account
Not needed, guest session
Price
Free during the beta
Files kept for
About 60 minutes, then deleted

Who uses it

When Protect PDF helps

AContracts and offers

Send agreements by email with the password shared another way.

BPayslips and statements

Protect personal financial documents in transit.

CClient deliverables

Release a report to the right person only.

DPersonal records

Lock scans of IDs, medical letters or tax papers before storing them.

Tips

Tips for better results

  • 01

    Use a long phrase rather than a short word, and send it by a different channel than the file.

  • 02

    Keep the password somewhere safe. A lost password cannot be recovered by us.

  • 03

    Add a watermark first if you also want the pages marked, then protect the final file.

FAQ

Protect PDF: common questions

Upload the PDF, tell EnDocs AI the password to use, and download the encrypted PDF.

Keep going

Related PDF tools

Ready to use Protect PDF?Start with your file.

Upload a PDF and EnDocs AI will take it from there. You can also summarize it or ask it questions in the same workspace.

Free during the beta. Files are removed after 60 minutes.