Password protect PDF privately
Add AES-256 opening-password protection to a PDF locally in your browser. Your file and password are not uploaded.
Private
Files stay on your device
Fast
Built for quick results
Browser-based
No software installation
Simple
Upload, process, download
Select one PDF
Choose or drag the PDF you want to password protect.
Supported format: PDF ยท Maximum file size: 25 MB
You can drag files here or use the browse button above.
How it works
How to password protect a PDF
Choose one PDF
Select an unprotected PDF up to 25 MB.
Create a password
Enter and confirm a strong password with at least 8 characters.
Protect and download
Encrypt the PDF locally and save the protected copy to your device.
Helpful tips
Get the best result
Use a strong password
Use at least 8 characters and combine words, numbers, or symbols that are difficult to guess.
Keep your password safe
Kukureku does not store your password and cannot recover it later.
Keep the original file
Password protection creates a separate encrypted copy and leaves your original PDF unchanged.
Frequently asked
Common questions
What kind of protection is applied?+
Kukureku uses the browser-based QPDF engine to create an AES-256 encrypted PDF that requires your chosen password to open.
Will my PDF or password be uploaded?+
No. The PDF and password are processed locally inside your browser.
Can Kukureku recover a forgotten password?+
No. Keep your password somewhere safe and retain the original unprotected PDF.
Keep working
Need another PDF tool?
Continue with another document task from the Kukureku PDF workspace.