Add a Password to a PDF
Add password encryption
Every other online tool for this asks you to upload the document and the password that protects it to a server you do not control. For the documents people actually encrypt, contracts, payroll, medical records, tax returns, that is usually the one thing they were trying to avoid. Here the encryption happens in this tab and neither the file nor the password leaves it.
What is Password Protect PDF?
Encrypt a PDF with a password using AES-256, the cipher recommended by the current PDF standard, without the file or the password ever leaving your browser. That last part is the whole point: every other online tool for this asks you to upload both the confidential document and the password meant to protect it to a server you do not control. You can set a password required to open the document, an owner password that restricts printing, copying and editing while still letting anyone read it, or both.
How do I use Password Protect PDF?
- Drop the PDF you want to protect.
- Set the password needed to open it, and confirm it.
- Optionally set a separate owner password and choose what readers may do.
- Press Protect PDF and download the encrypted file.
When should I use Password Protect PDF?
Use this before emailing anything confidential. To take a password off a file you already have, use Password Remover. To sign the document first, use PDF Signer. To reduce its size before sending, use PDF Compressor.
Frequently asked questions
What encryption is used?
AES-256, which is the only cipher recommended by ISO 32000-2, the current PDF standard. Older tools sometimes still use RC4, which is broken and should not be relied on for anything you actually care about.
What is the difference between the two passwords?
The user password is the one someone is asked for before the document will open at all. The owner password leaves the document openable by anyone but restricts what they can do with it: printing, copying text, editing, filling forms. Set only an owner password and readers are never prompted but are limited; set a user password and they cannot open it without it.
Can the password be recovered if I forget it?
No. That is the point of encryption that works. The key is derived through many thousands of hashing rounds, so there is no shortcut and no back door, here or anywhere else. Store the password before you send the file.
How strictly are the permissions enforced?
Permissions are enforced by the PDF reader, not by the file itself, so a compliant reader like Acrobat or a browser will honour them and a determined person with the right software can ignore them. Genuine confidentiality comes from the open password, not from the permission flags.
Should I turn off screen reader access?
Almost certainly not. That flag exists to let assistive technology read a document aloud, and turning it off blocks users who rely on it while doing nothing meaningful for security. It is left on by default here for that reason.
Is my file or my password sent anywhere?
Neither. The encryption runs in this tab. That is a real difference rather than a slogan: every other online tool that does this receives both your confidential document and the password protecting it on a server you do not control.
Can I protect an already protected PDF?
Not in one step; the tool will tell you if you try. Remove the existing password with Password Remover first, then protect it with the new one.
Is my file uploaded anywhere?
No. Everything runs in your browser. Your files never leave your device, and there is no server component for this tool.
Tools that pair well with Password Protect PDF
- Unlock PDF remove pdf passwords, free and in your browser.
- PDF Signer basic e-signature, free and in your browser.
- PDF Compressor shrink pdfs up to 80%, free and in your browser.
- PDF Merge Tool combine multiple pdfs, free and in your browser.