Protect PDF with Password
Lock a PDF with a password using AES encryption, and control printing and copying.
Your files stay on this device
or drop them here, or paste with Ctrl+V
PDF · up to 20 files · stays on your device
How to use Protect PDF with Password
- 1Add one or more files - drag and drop or tap to choose. Accepted: PDF.
- 2Adjust the settings if you need to - the defaults suit most people.
- 3Press “Protect PDF”. Processing happens on your device.
- 4Download your PDF, one by one or all together as a ZIP.
About this tool
PDF protection comes in two forms that offer very different security. An open password encrypts the file: without it the content is unreadable, even by software that ignores rules. That is genuine protection, and this tool applies AES with a 128 bit key, which every mainstream reader supports. Its strength depends on your password, so a passphrase of several unrelated words is far better than a single word. Permissions are the second form. The file opens for anyone, but flags ask readers to block printing, copying or editing. Well behaved software honours them and other software ignores them, so treat permissions as a polite request rather than a lock. Encrypt at the end of your workflow, since merging, compressing and numbering all need to read the file. Send the password by a different channel from the file itself, and keep a copy somewhere safe: the encryption is real, so nobody, including us, can recover the contents if the password is lost.
- Accepts
- Gives you
- Files at once
- Up to 20
- Processed
- On your device
Frequently asked questions
How strong is the encryption?
AES with a 128 bit key, as defined in the PDF specification and supported by all common readers. The practical strength depends on your password, so choose a long one.
What is the difference between the two protection modes?
An open password encrypts the file so it cannot be read without the password. Permissions leave the file readable but ask software to block printing, copying or editing, which only cooperative software enforces.
Can I recover the file if I forget the password?
No. We never see or store it, and there is no back door. Keep it in a password manager.
How strong is the encryption?
AES with a 128-bit key, supported by every mainstream PDF reader. Choose a long password - encryption is only as strong as the password.
Can you recover my password later?
No. We never see or store it. Keep it somewhere safe.
Is Protect PDF with Password free?
Yes. There's no sign-up, no watermark and no usage limit.
Are my files uploaded to a server?
No. Protect PDF with Password runs entirely in your browser. Your files never leave your device and nothing is stored - close the tab and everything is gone.
Which file types can I use?
PDF. Files are checked by their actual content, not just the extension, so renamed or damaged files are caught early.
Is there a file size limit?
Each file can be up to 200.0 MB, and you can process up to 20 files at once. Because processing uses your device's memory, very large files work best on a computer.
Does it work on my phone?
Yes. It works in modern mobile browsers on Android and iPhone. Heavier jobs (large PDFs, OCR) are faster on a computer.