Drop files here, or click to browse
One or more PDFs · up to 200 MB each
How to use
01
Upload the files
Drop one or more PDFs, up to 200 MB each. Each is listed, and any file that is already encrypted is flagged and skipped until you unlock it.
02
Set the password and permissions
Type the password in both fields or press Generate a strong password. Optionally limit printing and tick the actions to block, and add a permissions password if you want to lift them later.
03
Protect & download
Press Protect & download. One file saves with a -protected suffix and several arrive in a ZIP. Open one and test the password before deleting the originals.
Why Password Protect PDF
- A real AES-256 open password, applied in your browser.
- Seven permission controls, including low-resolution printing only, with an optional permissions password.
- Protect several PDFs with one password, with a strength meter and generator.
- The PDFs and password never leave your device.
Open password vs permissions restrictions
The two settings do different jobs. The open password is the real lock. The permissions only limit what someone can do after they have opened the file with that password.
When you set a permission without a permissions password, the tool sets a random owner password that is never shown, so people who open the file get the restricted view. You can still remove everything later with Unlock PDF and your open password.
| Open password | Permission restrictions | |
|---|---|---|
| What it does | Encrypts the content so the file cannot be read without it | Limits printing, editing, copying, comments, forms and page assembly |
| Where you set it | The Open password and Confirm password fields | The Permissions box, with an optional permissions password |
| Strength | Strong: AES-256 or AES-128 | Weak: some software ignores the flags |
| Use it for | Anything private, such as payroll, contracts and medical records | Extra friction on top of an open password |
The permission options explained
Each permission maps to a flag in the PDF standard. Readers that follow the standard grey out the matching menu items.
| Option | What the reader blocks |
|---|---|
| Printing: low resolution only | Printing is allowed, but only as a rough image, not at full quality |
| Block editing the content | Changing text and images in an editor |
| Block copying text and images | Selecting and copying content |
| Block adding comments | Notes, highlights and other annotations |
| Block filling in forms | Typing into form fields and signing them |
| Block page assembly | Inserting, rotating, deleting and reordering pages |
| Block text extraction for accessibility | Screen readers pulling out the text, which many modern readers still allow |
Common questions
Does this tool really encrypt the PDF in the browser?
Yes. It runs qpdf, a long-established open source PDF engine, compiled to WebAssembly, so AES-256 encryption happens inside your browser tab. The output is a genuinely encrypted document, and neither the file nor the password leaves your device.
How can I lock a PDF with a password for free?
Upload it here, set a password and download, with no account and no watermark. On a Mac, Preview can also do it through File, Export and the Encrypt option, and LibreOffice exports password-protected PDFs on Windows and Linux. All of these keep the file on your own machine.
What settings matter most when protecting payroll or HR documents?
Use a long password you have not used anywhere else, which the Generate button makes for you, and send it through a different channel from the file, such as a phone call or text. The tool always sets a real open password, so the content itself is encrypted.
Can I stop people printing or copying a password-protected PDF?
Yes. Set Printing to Block printing or to low-resolution only, and tick the actions to block, such as copying text and images. Adobe Acrobat and many other readers respect these settings, but some programs ignore them, so treat them as a deterrent. The open password is what keeps out people who do not have it.
What is the permissions password in Protect PDF?
It is a second password, sometimes called the owner password, that lets you remove the restrictions later in a program such as Acrobat. It must differ from the open password. If you leave it empty, the tool sets a random one that nobody knows, so the restrictions stay fixed.
Can I password protect several PDFs at once?
Yes. Drop all the files, set the password and permissions once and press Protect. Every file gets the same password and settings, and they download together in a ZIP.
Can recipients on old software open an AES-256 protected PDF?
Current versions of Adobe Acrobat Reader, Chrome, Edge, Firefox and macOS Preview all open AES-256 PDFs. If someone uses a very old reader, choose AES-128 under Encryption, which still uses AES but works with readers from the Acrobat 7 era onward.
How strong should a PDF password be?
Aim for at least 12 characters mixing upper and lower case, digits and symbols, or a long passphrase. The meter under the password turns green at Good and Strong. A short word can be guessed quickly by software, however strong the encryption is.
How do I remove the password from a protected PDF later?
Use Unlock PDF with the same password. It removes the encryption and any restrictions and gives you a normal copy. Without the password, neither tool can open the file.
What should I do with the unprotected original after emailing?
Remember the copies in your Sent folder and your downloads folder. Delete the plain version or move it somewhere private, because mailboxes are a far easier target than AES encryption.