Protect PDF
Add a password so only the right people can open your PDF.
How to use the Protect PDF
- Select the PDF you want to protect.
- Type the password to lock it with.
- Click Protect PDF and download the encrypted file.
About the Protect PDF
Protect PDF rewrites your document through Ghostscript with encryption switched on, setting the password you type as both the user password (needed to open the file) and the owner password (needed to change permissions). The result is a PDF nobody can open without the password, in any mainstream reader.
It is what you want before emailing a contract, a payslip or a statement. To take the password off again later, unlock PDF reverses it. If your goal is only to mark a document as private rather than lock it shut, a watermark is far less annoying for the recipient.
Be honest about the strength: this applies the older 128-bit standard security handler (revision 3), not AES-256. It is the level every reader can open and it stops casual access, but it is not modern encryption and should not be your only safeguard for genuinely sensitive material. Because the file is rewritten, bookmarks and form interactivity may not survive. Send the password by a different channel from the file — emailing both together protects nothing. Your PDF is uploaded to our server, processed under a random name in a folder blocked from web access, and deleted along with the password when the request ends; neither is stored or logged. One file, 20 MB, password up to 180 characters.
Frequently asked questions
How strong is the encryption?
It is 128-bit encryption at revision 3 — the widely compatible standard, not AES-256. Fine for keeping casual eyes out; not the right tool for high-value secrets.
Is there a separate owner password?
No. The password you enter is set as both the open password and the owner password, so anyone who can open the file also has full permissions on it.
Do you keep my password?
No. It is handed to the PDF engine for that single request and discarded with the temporary files when the request ends. It is never stored or written to a log.
What if I lose the password?
The file is unrecoverable. Nothing here can break an unknown password, so keep a copy of the original unprotected PDF somewhere safe.
Can I still edit or sign the protected file?
Not with the tools here — encrypted PDFs cannot be read for further processing. Do your merging, signing and page edits first, and protect the file last.