Password protect
Add an open password to a PDF (AES-256) · Pick another PDF tool from the left menu
1. Choose a PDF
2. Options
🔒 The password is used only inside your browser and is never sent to a server. Encrypts with an AES-256 open password.
3. Run
Everything runs inside your browser — neither files nor passwords ever leave it. For AI summaries and Q&A, use PDF Intelligence.
Merge, split, and compress PDFs in your browser, or add page numbers and passwords. Files are never sent to a server.
What you can do
- ✓Merge · extract pages · split into single pages
- ✓Add page numbers
- ✓Compression (image re-encoding)
- ✓Password protect and unlock (qpdf)
How to use
- 1Pick a tool on the left
- 2Upload a PDF and set the options
- 3Run it and download the result
Supported formats · PDF
Add an open password to a PDF with AES-256 encryption. Anyone without the password cannot read it, and anyone with it can open the file in Adobe Reader, Chrome, macOS Preview, or any standard viewer. Neither the password nor the document is sent to a server.
How to use it
- 1Select or drop the PDF to protect.
- 2Enter the password to set. Pick something easy to pass on to the recipient but hard to guess.
- 3Click Protect and download the encrypted PDF.
When it comes in handy
Use it for documents with personal data, such as résumés, payslips, medical certificates, or contracts, before sending them by email or messenger. If the file is misdirected or leaked, it stays unreadable without the password.
When an organization asks for documents containing ID numbers, the usual practice is to send the password through a separate channel, such as a text message.
How it locks the file
It uses the PDF standard's AES-256 encryption. The open (user) password and the permissions (owner) password are set to the same value, so anyone who knows it can view, print, and copy without restriction.
Any standards-compliant viewer opens the file: Adobe Acrobat, the built-in viewers in Chrome and Edge, macOS Preview, and phone PDF apps. Very old viewers may not support AES-256.
If you forget the password
There is no way to recover it. This site's Unlock tool removes protection when you know the password; it does not find unknown ones. Keep the unprotected original somewhere safe and share only the encrypted copy.
The password is used only for encryption inside your browser and is never stored anywhere.
Frequently asked questions
Is the password stored on a server?+
No. Both the password and the document stay inside your browser and are never transmitted.
Which programs can open the result?+
Any standard viewer: Adobe Acrobat Reader, the built-in viewers in Chrome and Edge, macOS Preview, and phone PDF apps, after entering the password.
Can I recover a forgotten password?+
No. There is no recovery. Keep the original in a safe place.
Can I block only printing or copying?+
This tool sets an open password. Permission-only restrictions that allow viewing but block printing or copying are not supported.
How do I change the password on an already protected PDF?+
Remove the current protection with the Unlock tool, then apply a new password with this tool.
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