Encrypt PDF

Lock PDFs with a password and choose what readers may do: print, copy, edit. AES-256 encryption, done in your browser: your files and passwords never leave your device.

Drop PDFs here

Each PDF is locked with the password you choose (AES-256 unless you pick an older level). One PDF or many: each gets the same settings. You can also drag one from Documents.

Protection

Mode

A password to open the PDF; nothing else is restricted.

The strongest, for every current PDF reader.

Anyone opening the PDF will need it; nothing else is restricted. It cannot be recovered if it is forgotten.

How to encrypt a PDF

  1. 1

    Add your PDFs

    Drop one PDF or many onto the page, or choose them from your device. They are read here, in your browser.

  2. 2

    Set the password

    One password in Simple mode; in Advanced, a password to open, a permissions password and what readers may do. One setting for every file.

  3. 3

    Encrypt and download

    Each PDF is encrypted on your device (AES-256 unless you choose an older level). Download them one by one or all at once as a ZIP.

Questions

How strong is the encryption?

AES-256 by default, the strongest encryption the PDF format offers, read by Acrobat and every current PDF reader. The PDF cannot be opened without its password.

Which encryption level should I choose?

AES-256 unless someone must open the PDF in old software: 128-bit AES for Acrobat 7 and later, 128-bit RC4 for Acrobat 5 and later, 40-bit RC4 only for the oldest readers (it can be broken quickly). At the three older levels a password has at most 32 Western European characters, and 40-bit RC4 can only restrict printing, changes, copying and comments.

Are my files or passwords uploaded?

No. The encryption runs in your browser with our own PDF engine. Your PDFs and the passwords you type never leave your device.

Can I protect many PDFs at once?

Yes. Add as many PDFs as you like: each gets the same password and permissions, and you can download them all as one ZIP.

What if I forget the password?

It cannot be recovered: that is what makes the encryption worth having. Keep your original file, or note the password somewhere safe.

What do the permissions do?

They tell PDF readers what someone who opens the file may do: print, copy text, edit, comment, fill in forms, change pages. Acrobat, browsers and most readers apply them. They are a request to the reader, not a lock like the password to open.

What is the difference between Simple and Advanced?

Simple sets only a password to open: anyone with it can open the PDF and do anything with it (the PDF format uses it as the permissions password too). Advanced sets two: a password to open (or none) and a permissions password for you as the owner, with what other readers may do: print, change, copy.

What is the permissions password?

The owner’s password: opening the PDF with it lifts every permission, and it is needed to change the protection later. Readers who open it with the password to open get only the permissions you allowed.

Can I change the protection of a PDF that already has a password?

Yes, with its permissions password: add the PDF and enter that password when asked, and the new protection replaces the old one.