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VellumPDF

Protect a PDF

A safe around your document.

Your files never leave your device

Drop your PDF here

or click to browse your files

How to protect a PDF with a password, step by step

A password encrypts the document with AES-256, right in your browser; usage rights can be restricted as well.

  1. Drop in the PDF

    If the file is already encrypted, the tool points this out and suggests unlocking it first; otherwise, the password form appears.

  2. Choose a password

    A three-bar indicator ranks its strength live — weak, fair, or strong — as you type.

  3. Confirm the password

    Retype it in the second field; a message flags right away if it doesn’t match the first.

  4. Restrict rights, if needed

    The “Restrict rights” section, collapsed by default, controls printing, copying, editing, comments, form filling and page assembly, with an optional owner password. “No password to open” lets the document open freely.

  5. Click “Protect the document”

    The button stays disabled until the two passwords match. When “No password to open” is ticked, this condition does not apply.

  6. Write the password down before closing the tab

    The encrypted file downloads with a reminder: without this password, no one — not even VellumPDF — can recover the content.

A document that is already encrypted cannot be protected a second time: the tool blocks the operation and suggests unlocking it first.

Frequently asked questions

What level of encryption does VellumPDF use to protect a PDF?

VellumPDF encrypts the document with a password using the AES-256 standard, a robust, widely used encryption method. An indicator shows the strength of the chosen password in real time as you type.

Are the password and document sent to a server?

No, encryption is computed directly in your browser: neither the file nor the password ever leaves your device. It is free and requires no account.

What happens if I forget the password I set with VellumPDF?

The protected file can no longer be opened without that password, and since VellumPDF keeps no copy of it, there is no way to retrieve it afterwards. Note it down carefully before closing the tab.

Does the password VellumPDF sets also prevent printing or copying the content once the document is opened?

Yes, if you ask it to. By default, a single password opens the file and grants every right. The “Restrict rights” section adds a separate “Owner password” and six settings: “Printing” (allowed, low quality or not allowed), “Copying text and images”, “Modifying content”, “Comments”, “Filling in forms” and “Assembling pages”. Standards-compliant readers such as Acrobat enforce these rights, but some programs ignore them: only the opening password truly protects the content.

How is the password strength shown while typing calculated?

A local indicator ranks the password into three levels, never transmitting it anywhere: weak under 8 characters, fair above that, strong from 12 characters combining at least one letter and one digit. This is a rough estimate of length and character variety, not a calculation of actual resistance to being cracked.

Why is a password starting with a dash rejected?

The embedded encryption engine only accepts passwords in a form where one starting with “-” would be read as a command option rather than a password, making the operation fail in a confusing way. VellumPDF detects this case before starting encryption and cleanly rejects the password instead of letting the error happen unnoticed.

Can the PDF open freely while printing is forbidden?

Yes: under “Restrict rights”, tick “No password to open”, then set the rights. The document opens without a password, but the rights you removed stay restricted in readers that honour them. If the “Owner password” is left empty, VellumPDF draws a random one that is never shown: keep the original if you will need to edit the document later.