Password-protect a PDF
This creates a password-protected, encrypted PDF entirely in your browser — free, with no signup, and with neither the document nor the password ever transmitted anywhere. Write the document in markdown and encrypt it on the way out, setting a password to open it and, separately, whether printing and copying are allowed. The privacy guarantee matters more here than anywhere else on the site: a tool that uploads your file in order to protect it has already defeated the point.
Open the editorHow to password-protect a PDF
Write or paste your document
Compose it in the editor, or paste in text you already have.
Set a password and permissions
Open the Security panel, set the password required to open the file, and choose whether printing and copying are allowed.
Download the encrypted PDF
Click Download PDF. The saved file is encrypted; the preview shows an unencrypted copy because browsers cannot display an encrypted PDF inline.
What you get
Open password
Require a password before the document can be opened at all.
Permissions
Separately allow or forbid printing and text copying, with an owner password controlling changes.
Nothing uploaded
The document and the password stay on your machine. No server ever sees either.
User passwords and owner passwords are different things
A PDF has two independent passwords and they do very different jobs. The user password — sometimes called the open password — is required before the file can be opened at all; without it the contents are unreadable. The owner password governs permissions on a file that is already open, such as whether printing or copying is allowed. Setting only an owner password gives you a document anyone can read but that politely asks readers not to print it, which is very often not what people mean by 'protected'. If the point is that only certain people can read the document, set the user password.
What encryption does and does not guarantee
The file is encrypted to the PDF 1.7 standard, which uses AES. That is genuinely strong, but the strength of the encryption is not the strength of your protection — the password is. A short or guessable password can be brute-forced offline by anyone who has the file, no matter how good the cipher, because there is nothing to rate-limit them. Use a long passphrase, and send it to your recipient through a different channel than the document itself. Emailing the PDF and the password in the same message is the most common way this protection is lost.
The limits of permission flags
Permission flags are honoured by conforming PDF readers, and every mainstream reader honours them. They are not, however, a technical barrier: a reader that chooses to ignore them can, and a determined person can strip them. Treat 'no printing' and 'no copying' as a clear statement of intent that ordinary users will respect — useful for a document circulated internally, or a draft you do not want casually redistributed. If the requirement is that a document genuinely cannot be extracted, no PDF setting delivers that, and it is better to know before relying on one.
What this does not do
- A lost password cannot be recovered — nothing is stored anywhere, so there is no copy to recover from.
- The preview shows an unencrypted copy, because browsers cannot render an encrypted PDF inline.
- Permission flags depend on the reader honouring them; they are not an absolute technical barrier.
- It encrypts PDFs it creates. There is no import to add a password to an existing PDF.
Frequently asked questions
- How strong is the encryption?
- The PDF is encrypted to the PDF 1.7 standard, which uses AES. Strength ultimately depends on your password, so use a long passphrase — a weak password can be brute-forced offline regardless of the cipher.
- Why does the preview show the document unencrypted?
- Browsers cannot display an encrypted PDF inline, so the preview renders an unencrypted copy and shows a notice. The downloaded file is encrypted.
- Can you recover my password if I lose it?
- No. Nothing is transmitted or stored, so there is no copy anywhere to recover. If you lose the password, the document cannot be opened.
- What is the difference between the two passwords?
- The user password is required to open the document at all. The owner password controls permissions — printing and copying — on a document that is already open. If you want only certain people to read it, set the user password.
- Can I add a password to a PDF I already have?
- No. This encrypts documents it generates. To protect an existing PDF you would need a tool that accepts an upload, which is exactly the trade-off this one avoids.
- Does 'disable printing' actually stop printing?
- It sets a flag that conforming PDF readers honour, and mainstream readers do. It is a clear statement of intent rather than an absolute technical barrier.
- Is the password sent anywhere?
- No. Encryption happens in your browser, so neither the document nor the password is ever transmitted. That is the main reason to use a local tool for this in particular.
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