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
Lock a PDF with a password using AES encryption, and control printing and copying. Your files are processed locally in your browser, so they're never uploaded, queued or stored — which also makes it fast. It's part of our free document security, which work together — you can pass the result straight into related tools below.
- 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, 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.