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Protect PDF

Protect a PDF with a password so that it only opens with it.

AvailableIn your browserInput: PDF

How to use: Protect PDF

  1. Choose the PDF you want to protect.
  2. Type the password twice and, if you like, adjust the printing, copying and editing permissions.
  3. Press Protect PDF and download the file; open it to check that it asks for the password.

What it accepts and what you get

Input
One PDF up to 25 MB that does not already have a password.
Output
A PDF encrypted with AES-256 that only opens with your password.
Where your data is processed
Your data is processed in your browser and is not sent to our servers.

Limitations and notes

  • If you lose the password the content cannot be recovered: TodoToolsOnline does not store it.
  • Permissions (printing, copying, editing) are honoured by most readers but are not a real barrier; what protects the file is the password to open it.
  • Some very old readers may not open a PDF with AES-256 encryption.

Frequently asked questions

Is my password or PDF sent anywhere?

No. Encryption runs in your browser with qpdf (WebAssembly); neither the file nor the password leaves your device.

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