Protect PDF
Add a password to a PDF so only people who know it can open the file. The document is encrypted with AES-256 — the strongest standard PDF encryption — entirely in your browser: neither the file nor the password ever leaves your device.
How to password-protect a PDF
- Add your PDF above — it stays in your browser while it's checked.
- Type the password the file should require. Use the show-password toggle to double-check it.
- Click Protect and download the encrypted copy.
About PDF encryption
Password-protecting a PDF is the simplest way to keep a document confidential on its travels — through email, chat apps, shared drives and backups, every stored copy stays unreadable without the password. It's the standard precaution for contracts, statements, medical or HR documents and anything else you'd rather not have opened by the wrong person.
This tool sets your password as both the open password and the permissions password and encrypts the file with AES-256 (the PDF 2.0 standard). The protection is real cryptography, not a soft lock: if the password is lost, the content is genuinely gone, so store it safely.
Frequently asked questions
How strong is the protection?
The file is encrypted with AES-256, the strongest encryption the PDF standard defines. Without the password, the content can't be read — not by other people, and not by us either, since nothing is uploaded.
What happens if I forget the password?
The file cannot be recovered — there is no backdoor or reset. Keep the password somewhere safe (a password manager is ideal), and keep an unprotected copy of the original if you might need it.
Will every PDF reader open it?
Current readers — Adobe Acrobat and Reader, Chrome, Edge, Firefox, Safari/Preview — all support AES-256. Only very old software (roughly pre-2010, before Acrobat 9/X) may fail to open it.
Is my PDF uploaded?
No. The encryption runs entirely in your browser via WebAssembly (qpdf); your document and the password you type never leave your device.