PDF Tools guide
How to password protect a PDF, free and without uploading it
To password protect a PDF, open it in a tool that adds a PDF password, type the password twice and save the protected copy. In PDF Tools that happens in your browser with AES-256, so the PDF never leaves your device, and the copy opens in any PDF app once the password is typed.
How to password protect a PDF, step by step
- Open PDF Tools and choose Add a password, then pick the PDF. (Already working on some pages? Add a password is also in the side list and the ⋯ menu.)
- Type a password twice, or tap Make one for me for four random words, and copy it somewhere safe.
- Choose what it allows once it’s open: printing and copying text are on unless you turn them off.
- Tap Add the password and download. You get a copy named …-protected.pdf; your original is unchanged.
- Send the PDF one way and the password another: the PDF by email, the password by text or a call.
Where it opens
The password is the standard kind built into the PDF, with AES-256 encryption (PDF 2.0’s strongest), so there’s nothing to install at the other end. It opens in Adobe Acrobat Reader, Preview on a Mac, iPhone and iPad (Files, Mail, Books), Chrome, Edge, Firefox and Safari once the password is typed. Forms in the PDF still fill in.
Very old PDF readers, from before about 2010, can’t open AES-256. If someone can’t, ask them to open it in a browser.
Why do it on your device
Most “protect PDF” websites upload the document to their server to add the password, which defeats the point for the kind of thing people protect: payslips, bank statements, medical letters, contracts. PDF Tools adds it in your browser: the encryption runs on your phone or computer with its built-in Web Crypto, and the file never leaves it.
Printing and copying limits
Turning off Allow printing or Allow copying text asks PDF apps not to let the reader do those things. Most respect it, but it’s a request built into the file, not encryption: someone determined can get round it. The password to open the PDF is what keeps it private.
To hide more than the pages
A PDF password encrypts the pages, but the file’s name and size still show, and it works only for PDFs. Lockbox locks any files, several at once, with their names hidden too. It can also put a PDF password on a single PDF, the same as here.
Questions
How do I password protect a PDF for free?
Open PDF Tools, choose Add a password, pick the PDF, type a password twice and tap Add the password and download. It’s free, with no account, and the PDF isn’t uploaded.
Can I password protect a PDF on my iPhone?
Yes. Open PDF Tools in Safari, choose Add a password and pick the PDF from Files. The protected copy saves back to Files, and opens in Files, Mail and Books with the password.
Will the other person need special software?
No. The password is built into the PDF the standard way, so Adobe Reader, Preview, Chrome, Edge and other PDF apps ask for it and open it.
How strong is the encryption?
AES-256 with PDF 2.0’s password handling, the strongest PDF readers support. A long password, or four or five random words, matters more than anything else.
Does Yuzool see my PDF or password?
No. Everything happens in your browser. Nothing is uploaded, and the password isn’t stored.
What if I forget the password?
There’s no reset: nobody can open the PDF without it, Yuzool included. Keep the password somewhere safe, or keep a copy of the PDF without one.