Protect PDF
Add a password to your PDF so only people with the password can open it. Real AES-256 encryption — free, no sign-up.
How to Protect a PDF with Password
Follow these 3 simple steps to add password protection to your PDF in seconds
Upload your PDF
Drag it into the box or click to choose a file (up to 50 MB).
Set a password
Type it twice. Longer passwords are harder to guess, so use 8 or more characters if you can.
Download protected PDF
It opens only with the password you set. Keep the password safe: if you forget it, the file cannot be recovered, not even by us.
Why use this Protect PDF tool?
Real AES-256 encryption with instant file deletion and complete privacy
Real encryption, not a trick
Your PDF is locked with AES-256, the same standard banks and governments use. Anyone without the password sees nothing.
Nothing is stored
Your file is encrypted on our server and deleted the moment your download is ready. We keep no copy.
Free, no watermark, no cost
Protect as many PDFs as you need, free. No subscription, no watermarks, and no sign-up required.
Works everywhere
Works seamlessly on phone, tablet, or computer right in your browser. No software or apps to install.
Frequently Asked Questions About Protecting PDFs
No. The file is encrypted and deleted immediately after your download is ready. A short automatic cleanup also removes anything left behind after 10 minutes, just in case.
AES-256, the strongest standard available for PDF password protection. The file cannot be opened without the password.
Then the file cannot be opened again — by you or by anyone else. There is no backdoor and no recovery. Write the password down somewhere safe before you download.
Yes — use our Unlock PDF tool with the same password to get an unprotected copy back.
No. Already-protected PDFs cannot be processed here. Unlock it first, then protect it again with the new password.
Yes, 50 MB per file, and up to 10 files per hour from the same connection, so the service stays fast for everyone.
Yes. Upload, set a password, and download — the whole thing works in your mobile browser.
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Ready to Protect Your PDF?
Add AES-256 encryption in seconds. No sign-up, no watermark — completely free.