Password protect a PDF
Add a password to open the document, and optionally a separate owner password that restricts printing, copying and editing. Uses AES-256, the strongest encryption the PDF format defines.
Runs in your browser — this file is never uploaded
or drop a file here
Encryption happens on your device — your password is never transmitted.
How to password protect a PDF
- 1Select your PDFChoose the document you want to lock.
- 2Set a passwordThe open-document password is the one that genuinely cannot be bypassed. A strength indicator shows how your choice holds up as you type.
- 3Choose what readers may doOptionally allow or block printing, copying, editing and commenting, then download. Encryption happens on your machine, so the password is never transmitted.
When you would use this
Encryption is for documents that travel: payslips and tax paperwork sent by email, medical or legal records shared with a third party, or board material circulated before a meeting. Email itself is not private, so a password on the file is what actually protects it in transit. Permissions are useful separately, when you are happy for someone to read a document but not print or extract from it.
Questions about Protect PDF
- Are my files uploaded to a server?
- No. Every tool on this site runs inside your browser. Your file is read from your disk into your own browser's memory, processed there, and written back out. You can confirm this yourself: open your browser's developer tools, switch to the Network tab, and run the tool — you will not see your document being sent anywhere. It also means the tools keep working if you go offline after the page has loaded.
- What is the difference between the two passwords?
- The user password is required to open the document at all. The owner password does not restrict opening, but it locks the permissions — so you can let anyone read a file while preventing them from printing it or copying text out of it. You can set either one, or both.
- How strong is the encryption?
- AES-256, which is the strongest cipher the PDF specification supports and what current versions of Acrobat use. The encryption happens on your own machine, so your password is never transmitted anywhere.
- What happens if I forget the password?
- Nothing can be done — that is the point of real encryption. There is no recovery path and no back door. Store the password somewhere safe before you close the tab.
- Will the password work in Acrobat, Preview and on my phone?
- Yes. AES-256 is part of the PDF specification, so any current reader handles it, including Adobe Acrobat, Apple Preview, Chrome and the PDF viewers built into Android and iOS.
Other tools you might need
Unlock PDFStrip password protection from a PDF you have the password for.Redact PDFPermanently remove sensitive text and images, not just cover them.Merge PDFCombine several PDFs into one, in exactly the order you choose.Split PDFPull out single pages, custom ranges, or break a file into separate documents.