Protect PDF
Add a password to your PDF so only people who know it can open the file — free, with nothing to install.
- Your PDF and password stay on your device.
- AES-256, the strongest encryption PDFs support.
- Choose whether people can print, copy or edit.
- Opens in Acrobat, Preview, Chrome and phone viewers.
Encryption runs entirely in your browser with JavaScript. Your password is never sent anywhere or saved.
How to password protect a PDF
Before you email a contract, payslip, medical report or ID scan, lock it with a password. Share the password separately — by phone or text message — so the file and the key never travel together.
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Add your PDF
Drag a PDF onto the tool above, or tap Choose file to pick one from your computer or phone.
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Set a password
Type a password twice. Untick Print, Copy or Edit if people shouldn't be able to do those things.
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Download the protected PDF
Click Protect PDF. An encrypted copy saves to your downloads folder, and your original stays unchanged.
Real encryption, not just a lock icon
A password-protected PDF is scrambled with AES-256. Without the password, the pages are unreadable — whether the file is forwarded, lost on a USB stick or left in a shared folder.
- Nothing uploaded
- Uploading a file to protect it defeats the purpose. Here, the PDF is encrypted by your own browser and never leaves your device.
- AES-256 encryption
- The same standard used by banks and governments, and the strongest option in the PDF specification.
- Control what people can do
- Let people read the file but stop them printing it, copying text out of it or changing it.
- Nothing else changes
- Text, images, links, form fields and bookmarks stay exactly as they were. The file isn't compressed or re-rendered.
Choosing a strong password
Encryption is only as strong as the password behind it. A short or common password can be guessed by software in minutes; a long one can't.
| Password style | Example | Strength |
|---|---|---|
| A word or name | sunshine | Weak — guessed almost instantly |
| Name plus year | Priya2024 | Weak — a common pattern |
| Short mix of characters | K7#qm2 | Fair — too short |
| Four or more random words | lamp-river-ticket-oak | Strong — long and easy to say aloud |
Protect PDF questions
Is it free to password protect a PDF here?
Yes. It's completely free, with no sign-up, no watermark and no daily limit.
How secure is the password protection?
Files are encrypted with AES-256, the strongest encryption in the PDF standard. With a long, unique password, the content can't be read without it.
Is my PDF or password uploaded anywhere?
No. The PDF is encrypted inside your browser. Neither the file nor the password is sent to a server or stored.
What happens if I forget the password?
The file can't be opened, and nobody can recover the password for you. Keep the original unprotected PDF somewhere safe, or store the password in a password manager.
Do printing and copying restrictions really stop people?
Adobe Acrobat, Chrome, Edge and most PDF readers respect them. Some tools ignore them, so treat restrictions as a clear signal rather than a guarantee. The open password itself is real encryption.
Will the protected PDF open on phones and Macs?
Yes. AES-256 protected PDFs open in Adobe Acrobat Reader, Apple Preview, Chrome, Edge, Firefox and the built-in PDF viewers on iPhone and Android.
How do I remove the password later?
Use the Unlock PDF tool. Enter the password once and it saves a copy without it.