Protect PDF with a password
Encrypt your PDF so only people with the password can open it.
Use at least 8 characters for real protection.
What may readers do after they open it?
Done
How to password protect a PDF
- Drop the PDF onto the box above, or click it to browse. One document at a time.
- Type your password, then type it again underneath. The button stays disabled until the two match, and the small meter tells you whether what you have chosen is very weak, fair or strong — eight characters is the sensible floor.
- Decide what readers may do once they are in. Printing and copying text are permitted by default; editing is not. Untick anything you would rather block.
- Press “Protect PDF”. The encrypted copy downloads with -protected added to the filename, and from then on Acrobat, Chrome, Edge, Preview and phone readers will all ask for the password before showing a single page.
What people use it for
Encryption is worth the small extra step whenever a file is about to travel through email, chat or a shared folder, where forwarding is easy and access lists drift over time.
- Emailing a payslip, a tax return or a bank statement to an accountant.
- Sending medical results or an insurance claim where the inbox is shared with a family member.
- Handing over a contract draft or a price list that should not circulate beyond one recipient.
- Archiving scanned ID documents, deeds or certificates on a laptop that leaves the house.
- Distributing a training manual you would rather readers did not edit and re-issue as their own.
Good to know
Write the password down somewhere safe before you close the tab. The file is encrypted with AES using the password you typed, and that password is not stored — not in this page, not in a database, not anywhere. There is no reset link and no support address that can help: if you forget it, nobody, ourselves included, can open the document again. That is the honest trade for encryption that genuinely works.
Two practical limits. A PDF that is already password protected cannot be re-encrypted; you will get a clear message asking you to remove the existing password first, which Unlock PDF does. And the permission tick-boxes are instructions that well-behaved PDF readers obey — they are not a technical barrier, since anyone who has the password to open the file already has the content in front of them. Consider them a clear signal of intent rather than a lock — a visible watermark across the pages makes the same point rather more plainly. Everything happens inside your browser, and that is the whole point on this particular page: an upload-based site receives two secrets in the same request, the confidential document and the password meant to guard it. Here neither one leaves your computer, so there is nothing on anyone's server to leak.
Questions people ask
What kind of encryption is used?
AES, applied to the document itself, with your password as both the user and owner password. The result is a standard encrypted PDF that any modern reader understands — nothing proprietary and nothing that needs EditZap to open it later.
Can I remove the password again afterwards?
Yes, as long as you still know it. Unlock PDF strips it back off and gives you an ordinary file. It cannot help if the password has been forgotten.
Does it work on a large or scanned document?
Usually, though very large scans are held in memory while they are encrypted, so an older phone may struggle where a desktop will not. Running Compress PDF first often makes the job comfortable.
How strong should the password be?
Long beats clever. Three or four unrelated words are easier to remember and harder to attack than a short string of substituted symbols. Avoid anything you have used elsewhere, and send it to the recipient by a different channel than the file itself.