How to password protect a PDF online
- 1
Select your PDF
Click “Select PDF file” or drag and drop your document into the box above.
- 2
Set a password
Type a password and repeat it. The strength meter helps you choose a good one. Use the Show button to check what you typed.
- 3
Choose what people can do
Leave everything ticked for full access with the password, or untick printing, copying or editing to restrict them.
- 4
Protect and download
Click “Protect PDF” and your encrypted file downloads straight away. Nothing is uploaded or stored.
Why use Protect PDF
AES-256 encryption
The same strong standard used by banks and governments. Your PDF cannot be opened without the password.
Private by design
Encryption happens inside your browser. Your PDF and your password never leave your device.
Print, copy and edit controls
Decide whether readers can print, copy text or edit the file, in addition to needing a password to open it.
When to password protect a PDF
Email, chat apps and cloud links can be forwarded or leaked. A password means a stray copy is still unreadable. Typical uses:
Contracts and legal files
Send agreements and NDAs knowing only the person with the password can open them.
Payslips and tax documents
Keep salary, bank and tax details private when you email them.
Medical and personal records
Protect IDs, reports and certificates that contain sensitive information.
Paid or exclusive content
Share ebooks, course notes and reports that you do not want copied or edited.
Open password and permissions explained
| Setting | What it does |
|---|---|
| Open password | Required to open the PDF at all. Without it the content stays encrypted and unreadable. |
| Printing | Untick to stop the file being printed or saved as a printout. |
| Copying text | Untick to stop readers selecting and copying text and images out of the PDF. |
| Editing | Untick to stop changes to pages, forms and annotations in PDF editors. |
| Owner password | When you restrict anything, we create a random owner password so the limits cannot be removed with the open password. |
Tips for a strong PDF password
- Use at least 12 characters and mix upper and lower case, numbers and symbols, or a long phrase of several words.
- Do not reuse the password from your email or bank, and never send it in the same message as the file.
- Store the password in a password manager. We cannot recover it for you, because nothing is stored on our side.
- Keep an unprotected copy of the original somewhere safe in case you forget the password.
- Want to mark the document too? Add a watermark or your signature before protecting it, because a protected file cannot be edited afterwards.
- Need to open or edit a protected file later? Use Unlock PDF with the password.
Protect PDF: frequently asked questions
Is it free to password protect a PDF here?
Yes. There is no sign-up, no watermark and no limit on how many files you protect. It is free to use.
Is my PDF uploaded to a server?
No. The encryption runs inside your own browser, so neither your document nor your password ever leaves your device.
How strong is the encryption?
Your PDF is encrypted with AES-256, the strongest encryption in the PDF standard. Security then depends mostly on how strong your password is, so choose a long one.
I forgot the password. Can you recover it?
No. We never see or store your password, and AES-256 cannot be broken without it. Always keep an unprotected copy of the original and store the password safely.
Can I stop people printing or copying my PDF?
Yes. Untick Printing, Copying text or Editing before you protect the file. Most PDF apps respect these limits, but they are not a guarantee against every tool, so rely on the open password for real security.
What is the difference between an open password and an owner password?
An open password is needed to view the file. An owner password controls permissions such as printing and editing. When you restrict something we create a random owner password for you.
Will the protected PDF open on any device?
Yes. Password-protected PDFs open in Adobe Acrobat, Chrome, Edge, Firefox, Safari, Preview and mobile PDF apps. The viewer will ask for the password.
Will the quality or layout change?
No. Encryption does not change how pages look. The content is simply locked, and the file size stays almost the same.
Can I protect a PDF that already has a password?
Not directly. Remove the old password first with Unlock PDF, then protect the unlocked copy with a new password.
Can I protect a PDF on my phone?
Yes. The tool works in modern mobile browsers on Android and iPhone. For very large files a laptop or desktop is faster because processing happens on your device.
What is the maximum file size?
You can protect PDFs up to 50 MB. For larger files, reduce the size first with our Compress PDF tool.
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