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PdfDady

Password protect a PDF

Add a password before you email a salary slip, statement or ID copy. The PDF is encrypted with AES-256 in your browser, and anyone opening it will need the password.

1. Add a PDF

2. Set a password

Anyone with this password can open the file.

If you forget the password, the protected file can't be opened and PdfDady can't recover it. Keep your original, and share the password separately from the file. PdfDady doesn't store or send your passwords.

Add a PDF to protect.

How to add a password to a PDF

  1. Add your PDF

    Choose one PDF, up to 100 MB.

  2. Choose a password

    Type it twice. Longer is stronger: a few words make a good password.

  3. Optional: restrict printing or copying

    Tick what people may do, and set a separate permissions password that lets you lift the limits later.

  4. Protect and download

    Press Protect PDF and save protected.pdf. Keep your original too.

What you can do with this tool

  • AES-256 encryption

    The strongest standard PDF encryption, supported by current PDF readers. Very old readers (before Adobe Reader X, 2010) may not open it.

  • Optional permissions

    Block printing, copying or editing for people who only have the open password.

  • Password strength hint

    Short passwords get a warning, because the password is what protects the file.

  • Content unchanged

    The pages are encrypted, not changed. Text, links and bookmarks are kept.

  • Stays on your device

    Encryption runs in your browser with qpdf. Your file and password are not uploaded.

What you get

InputOne PDF, up to 100 MBNot already password-protected
EncryptionAES-256 (PDF 2.0 / Acrobat X and later)
PermissionsPrinting, copying, editingRespected by most readers, ignored by some software
ContentUnchanged
Forgotten passwordCan't be recoveredKeep your original file
OutputOne PDF named protected.pdf

Frequently asked questions

How do I add a password to a PDF?

Add the PDF, type a password twice, press Protect PDF and download protected.pdf. Opening it will ask for the password.

How secure is AES-256?

The encryption itself is strong. The weak point is the password: a short or common one can be guessed. Use 8 or more characters, ideally a few unrelated words.

What is the permissions password?

A second password that controls printing, copying and editing. People with only the open password get the limits you set; the permissions password lifts them.

Can I stop people printing or copying?

You can set those limits and most PDF readers respect them, but some software ignores them. Don't rely on them for anything secret; the open password is the real protection.

What if I forget the password?

The protected file can't be opened and PdfDady can't recover it. Keep your original file somewhere safe.

Will it open on phones and older readers?

AES-256 is part of the current PDF standard and supported by today's PDF readers. Very old readers (before Adobe Reader X, 2010) may not open it. Open the file once yourself before sending it.

Is my PDF or password uploaded?

No. The PDF is encrypted in your browser. PdfDady doesn't upload the file or store or send the password.

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