Protect PDF
Add a password to your PDF so only people who know it can open it, encrypted with AES-256. No upload, no signup, no watermark.
Files stay on your device How it works
Drop files here, paste, or
PDF · up to 10 files, 100 MB each
Your files
Your file is ready
Keep a PDF private when you send it
Bank statements, contracts, medical letters, payslips: some documents shouldn’t be readable by anyone who happens to see the email or find the file. A password on the PDF itself protects it wherever it goes, in an inbox, on a shared drive or on a lost phone. Send the password separately, by a different route such as a text message or a call, so the file and its key never travel together.
How to protect a PDF
- Choose up to 10 PDFs, each up to 100 MB. They all get the same password.
- Type a password, then type it again to make sure there’s no typo.
- Press Protect the PDF and download the protected copies. Each one is named with “-protected” added.
What the protection does
The whole file is encrypted with AES-256, the method of the current PDF standard, and the password is needed to open it. Every common PDF reader asks for it: Adobe Acrobat and Reader, browsers, and the readers built into phones and computers. Once opened with the password, the PDF works as usual, so printing and copying aren’t limited.
Choosing a password
- Length beats cleverness: three or four unrelated words are easier to remember and harder to guess than a short mix of symbols.
- Avoid the obvious: a name, a birthday or the document’s own title are the first things anyone would try.
- Keep it safe: nobody can recover a forgotten password, this site included. Keep the original file or note the password in a password manager.
Sending a protected PDF
- Split the file and the key: email the PDF, then share the password by text message, a phone call or a password manager’s sharing feature.
- One password per recipient where it matters, so a leaked password exposes only one copy.
- Tell them what to expect: “The file asks for a password; I’ll text it to you.” It saves a confused reply.
Good to know
- Already protected PDFs are refused. Remove the old password first with Unlock PDF, then protect the file again.
- Very old readers made before 2008 may not open AES-256 files. Anything current does.