Protect a PDF With a Password

AES-256 encryption, done in your browser. The file and the password never leave your device.

Protect PDF

Add a password so the PDF can only be opened by people who know it. AES-256 encryption, done on your device.

Select from device or drop a PDF here Processed on this device. Never uploaded.

How it works: the file is encrypted with AES-256 in your browser; the password never leaves this page. A strong password (long, not a word from the dictionary) matters more than anything else. Every page counts toward the free daily limit.

The short version

Drop in a PDF, type a password twice, download the protected file. Anyone who opens it will need the password. Neither the file nor the password is uploaded.

How to use it

  1. Drop your PDF into the box above.

  2. Type a strong password twice and choose whether printing and copying text are allowed.

  3. Click "Protect PDF", download, and open the file once with your password to check it works.

Good to know

  • Write the password down. It is never sent or stored anywhere, so nobody — including us — can recover it or open the file without it.
  • The encryption is AES-256, the strongest standard PDF encryption. The weak point is usually the password: use a long one that isn't a dictionary word.
  • Printing and copying limits are respected by most PDF apps, but some apps ignore them — treat them as a courtesy, not as protection. The password to open the file is the real protection.
  • Sending the file and the password through different channels (for example email and a phone call) keeps them apart.
  • Every page counts toward the 15 free pages a day.
Most online PDF tools

Upload your document to a server, process it there and send the result back.

StayPutPDF

Works inside your browser. Your document never leaves your device — useful for contracts, statements and anything confidential.

Free and Premium

Free

15 pages a day

  • Every tool except OCR — merge, split, organize, compress, redact, sign, edit, page numbers, protect, convert (incl. PDF to Word and JPG), extract text
  • No watermark, no account, no email
  • Counted across all tools; the count resets every day
Premium

$9/month

  • No page limit on any tool
  • OCR: make scanned PDFs searchable, 39 languages
  • Your signature saved on this device (never uploaded), and your signature or initials on every page in one click
  • One-click form filling with your saved details — name, address, email
  • Or $69/year · $149 once, for life

Free or Premium, the tools work the same way: your files never leave your device.