Protect PDF with a password
Encrypt a PDF with a password right in your browser. The file and the password never leave your device.
Drop a PDF or click to choose
Protect your PDF with AES-256 encryption. 100% private — processing happens in your browser.
How to password-protect a PDF
- Drop one or more PDFs into the box above.
- Type the password people will need to open the file.
- Optionally open Advanced options to set an owner password and turn off printing, editing or copying, or to choose AES-128 instead of AES-256.
- Click Protect and download the encrypted PDF.
How PDF protection works in MiniFiles
- Processed on your device. Encryption is done by qpdf compiled to WebAssembly, running in your browser tab. Neither the PDF nor the password is sent anywhere.
- Strong encryption. AES-256 by default, with AES-128 available for older PDF readers. Anyone opening the file must enter the password.
- Keep your password safe. MiniFiles never sees or stores it, so a forgotten password can't be recovered.
- Permission restrictions. With an owner password you can block printing, editing or copying text and images. Leave the open password empty to share a PDF anyone can read but not print or copy. Standard PDF readers enforce these restrictions.
- Compress first. Turn on compression before protecting to get a smaller encrypted file in one step.
- Free to use. Each protected file counts as one use. Without an account you get 10 uses a day across all tools; a free account removes the daily limit. No file size limit on any plan.
Step-by-step guide: how to password-protect a PDF without uploading it.
Frequently asked questions
Is it safe to password-protect a PDF online?
With MiniFiles the PDF is encrypted inside your browser by qpdf (WebAssembly), so the file and the password are never uploaded to a server.
Which encryption does MiniFiles use?
AES-256 by default. You can pick AES-128 if the PDF must open in very old readers.
What is the owner password?
An optional second password that controls permissions. With it you can block printing, editing or copying for everyone who opens the PDF with the open password. Without it, the open password is used for both.
Can I stop people from printing or copying my PDF?
Yes. Set an owner password in Advanced options and turn off printing, editing or copying. You can leave the open password empty so the PDF opens normally but stays restricted in standard PDF readers.
Can MiniFiles remove a password or recover a forgotten one?
No. MiniFiles only adds protection, and it never stores your password, so it can't recover one.
Is PDF password protection free?
Yes, on every plan. Without an account you get 10 uses a day across all tools; a free account removes the daily limit. No file size limit on any plan.
More private PDF and image tools
Every MiniFiles tool runs in your browser — your files are never uploaded.