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Protect a PDF with a password
Lock a PDF so that it asks for a password to open. Uses 256-bit AES encryption, applied on your device.
How to protect PDF
- Choose your PDF.
- Enter a password and confirm it.
- Select Protect PDF and download the locked copy.
Your file never leaves this tab.
Protect PDF runs as code inside your browser. The document is read from your device, changed in memory, and handed back to you as a download. There is no upload step and no copy on our servers.
That also means it keeps working on a plane or a slow connection once the page has loaded.
Check it yourself
- Open your browser developer tools and go to the Network tab.
- Use the tool on a file.
- You will see no request carrying your file anywhere.
Questions about Protect PDF
How strong is the protection?
The file is encrypted with 256-bit AES. The real strength depends on your password, so use a long, unique one.
What if I forget the password?
It cannot be recovered. We never see it, and it is not stored anywhere. Keep it in a password manager.
Does this restrict printing or copying?
It sets a password to open the file. Anyone with the password can print and copy.
Is my password sent anywhere?
No. Encryption runs in your browser and the password is never transmitted.
About protect pdf Tool
The protect pdf tool at Kyvorix is built to run 100% in your browser. Your file is read locally, processed in memory and returned as a download. No upload, no storage on our servers, works offline.
Free to use, no sign-up, no watermark. Perfect for students, offices and anyone who needs quick PDF jobs without risking privacy.
Benefits
- Private: file never leaves your device
- Fast: no queue, instant processing
- Free: no limits, no account needed
Frequently Asked Questions
Is this tool free?
Yes, 100% free, supported by ads.
Do you upload my file?
No, everything runs in your browser offline.
Works on phone?
Yes, Chrome, Safari, Firefox on mobile and desktop.