Secure & archive · guide
What Protect PDF does
Protect PDF adds a password that must be entered to open the file, encrypting it with AES-256, and records whether printing, copying text, editing and commenting are allowed. The encryption runs in your browser, so neither the document nor the password is sent to any server. Keep the password safe: without it, the protected copy cannot be opened by anyone, Filozy included.
How to protect PDF in your browser
- Choose one PDF Select the PDF you want to protect. It opens in this browser tab and is not uploaded.
- Set the password and permissions Enter the password to open the document and type it again; the note under the first box estimates its strength as you type, and the two must match before anything is encrypted. Then choose whether to allow printing, copying text, editing and commenting.
- Protect and save Select Protect, save the encrypted copy, and open it once with the password to confirm it works before you delete any unprotected version.
Worked example
Create a password-protected copy for an authorised recipient.
- Starting point
- Choose the PDF and prepare a strong password that you can share through a separate suitable channel.
- What to do
- Set the password and supported permissions, export, close the result and reopen it with that password.
- Result
- Expect an encrypted PDF copy. Test access before deleting any unprotected original you still need.
If the result is not right
If opening fails, check the exact password and keyboard layout. Return to the original to create a new protected copy rather than assuming a recovery method exists.
Limits worth knowing
- Reader permissions are not a substitute for controlling recipients. Losing the password may make the protected copy inaccessible.
Questions and answers
What does the strength note under the password mean?
It is a rough estimate, worked out in this tab, of how hard the password would be to guess, given in bits: under 40 is marked weak, under 60 fair, under 80 strong, and anything above very strong. It counts the kinds of character you used and discounts repeated ones. A passphrase of several unrelated words scores higher than a short word dressed up with symbols, and is easier to remember.
Can I let people open the PDF but stop them printing or copying it?
Only as a request, and a weak one here. The Allow choices are permission flags stored in the file. The password you set also counts as the permissions password, so a reader that follows the PDF standard treats anyone who opens the file with it as the owner and gives them full access, whatever the Allow boxes say. Other readers ignore the flags, and anyone who can open the file can clear them, Unlock PDF included. Printing is allowed by default and the rest are off, and screen readers can always read the text even with copying blocked. If something must not be copied, redact it before you share the file.
What stops me locking myself out with a typo?
You type the password twice, the second box says whether the two entries match as you type, and if they differ nothing is encrypted. That check matters because there is no reset: the password never reaches Filozy, so nobody can recover it for you. Open the protected copy once with the password before you delete any unprotected version.
How do I change or remove the password on a PDF?
Protect PDF will not add a password to a file that already needs one to open; it asks you to unlock it first. Open the file in Unlock PDF with the current password, which saves an unprotected copy, then protect that copy with the new password, or keep it as it is to remove protection. Unlocking rebuilds the file, so its bookmarks and attachments do not come through.
Does protecting change anything else in the PDF?
No. The same document is encrypted as it stands, so its pages, bookmarks, links and form fields stay as they were, and the copy is saved with -protected added to its name. Only what you set changes: the open password and the four Allow choices.
Why encrypt a PDF on my own device rather than on a website?
Because encrypting on a website's server means sending it both the unprotected document and the password meant to protect it. Here the encryption and the strength estimate both run in this tab: the page's code comes from filozy.com, but the document and the password stay on your device.