Protect a PDF with a password
Encrypt your PDF so only the password opens it, in your browser. Stays on your device. Nothing is uploaded.
Choose files
or drop them here
Ctrl+V to paste from the clipboard
up to 1 file, 25.0 MB each
Stays on your device. Nothing is uploaded.
How to protect pdf
- Choose one PDF, or drop it on the page.
- Type the password that should be required to open it.
- Press Protect. The document is encrypted on your device.
- Download the protected PDF and store the password safely.
What the password actually does
Protection encrypts the document with AES, the standard PDF security handler. Opening the file then requires the password: viewers, printers and web portals all ask before showing a single page. Printing stays allowed at full resolution, and text copying is left on, because a document you can open is usually a document you legitimately need to work with; modification and page assembly are blocked.
The encryption runs entirely on your device using a WebAssembly build of pdf-lib with security support. Your password never leaves the tab: there is no account, no reset link and no server that has seen it. That is also why a forgotten password cannot be recovered here; keep it somewhere safe before you lose it.
The jobs it exists for: sending a signed contract by email, archiving an ID scan, putting a payslip in a shared drive, and any moment a file leaves your hands and should not be readable by strangers.
Limits and honest notes
One document per run. Already-protected files are refused, since re-encrypting an encrypted file needs its existing password; unlock first if you hold it.
PDF encryption is good at keeping casual readers out, but no password scheme survives a determined attacker with unlimited time and a weak password. Choose at least twelve characters for anything that matters.
Up to 25 MB per document. Everything runs in this tab; the password is used in memory and discarded.
Frequently asked questions
Can you recover my password if I forget it?
No. The password is never sent anywhere, so there is nothing to recover from. Keep it in a password manager before you encrypt.
What encryption is used?
The standard PDF security handler with AES, applied by a WebAssembly build of pdf-lib with security support. Viewers everywhere honour it.
Can people still print the protected file?
Yes, at high resolution. Copying text is allowed too; editing and page assembly are blocked.
Is my password uploaded?
Never. It is used inside your browser and discarded when the tab closes.
Private by design
Stays on your device. Nothing is uploaded. The conversion runs in your browser: open the Network tab while you convert and you will see that nothing is sent. No account, no watermark, no daily limit.