Protect your PDFs with a password

Updated 28 September 2026

To protect a PDF with a password, drop it here, type the password and press Protect. Your browser encrypts the file on your device, and whoever opens the copy must enter the password before the reader shows a single page.

It is worth doing for any file that leaves your hands: a tax return on its way to an accountant, HR records in cloud storage, or a scan handed over on a memory card.

How to add a password to a PDF

1. Drop the PDF, or a folder of them, into the drop zone.
2. Enter a password, then set whether printing and text copying are allowed.
3. Press Protect.
4. Save the protected copy, then open it once to confirm the password prompt appears.

What the encryption does

The file is locked with 256-bit AES. No encryption in the PDF standard is stronger. Every current PDF reader supports it, on computers, in browsers and on phones. A reader asked to open it without the password shows nothing.

Nothing else about the document changes. Text, links, images and the pages themselves stay untouched, and the file ends up about the same size.

Choosing a password that holds up

Encryption is only as strong as the password behind it. A single dictionary word is guessable by software. Chain four or five words that have nothing to do with each other, and the passphrase becomes, in practice, too long to guess.

Share the password by another route than the file. If both travel in one email, whoever sees that message has everything needed to open the file. A text message or a phone call does the job.

Forgetting the password locks everyone out, us included. Hold on to the unprotected original, or let a password manager remember the password for you.

Print and copy permissions

Out of the box, the protected file can be printed, but its text cannot be copied. Both settings can be switched. Mainstream readers honor them, yet they are a request, not a hard block, once the file is open.

Protecting a whole set of PDFs

All of the encryption happens in your browser, and the unencrypted PDFs are never uploaded. That is the point: the documents worth a password are the ones that should not travel anywhere unprotected. There is also no account, no batch cap and no daily allowance. Files up to 50 MB are free, and Pro handles up to 500 MB. Speed depends on your device. Save the results one by one or as a single ZIP.

For staff contracts or a quarter's invoices, a pipeline puts the same password on every file in one run and can chain other steps around it. Pipelines are free to try on up to 3 files, and Pro runs them on up to 500.