Password protect PDF
Add a password to a PDF so it cannot be opened without it. The file is encrypted with AES-256, the strongest encryption PDF supports. It all runs in your browser, so neither the PDF nor your password is ever uploaded.
How to password protect a PDF
Password protect a PDF without uploading it
A password on a PDF keeps it private while it travels: as an email attachment, on a USB stick, in a shared folder or in cloud storage. Contracts, medical records, payslips and scans of ID cards are the usual candidates. Without the password, the file shows nothing at all.
Most sites that add a password ask you to upload the file first, which means a copy of your private document and the password both pass through someone else's server. Here they do not. The PDF is read from your device, encrypted in your browser and saved back to your device, and the password is forgotten once the copy is made. One PDF is protected at a time, with no account to create and no watermark added.
Choose a password for your PDF
Drop one PDF of up to 60 MB, then type a password of at least 6 characters in both boxes. Typing it twice catches a typo that would otherwise lock you out of your own file; if the two do not match, you see "The two passwords don't match." Press Show to see what you typed. Any letters work, including accents and other alphabets, but plain letters, digits and common symbols are the safest choice if the file will be opened on other devices.
Six characters is the minimum, not a good length. A phrase of three or four unrelated words is easier to remember than a jumble of symbols and much harder to guess. Send the password by a different route than the file: if the PDF goes by email, give the password by phone or message.
AES-256 PDF encryption
Press Protect PDF and the new file is ready in a moment, named after the original with -protected added, so contract.pdf becomes contract-protected.pdf. It is encrypted with AES-256, the strongest method the PDF standard has. Text, images and attachments inside the file are all encrypted. The file you started with is not changed and stays unprotected.
Adobe Acrobat Reader and the PDF viewers built into Chrome, Edge and Firefox ask for the password and then open the file normally. Very old PDF software that predates AES-256 may not open it. The password you choose is used both to open the file and as its owner password, so whoever knows it can also print, copy and change the protection. This tool does not set separate printing or copying limits.
Keep the password safe
Nobody can open the protected copy without the password, and that includes us: the password is never sent to a server or saved, so there is no reset link and no way to recover it. Store it in a password manager or somewhere you will find it later, and keep your original file in a safe place too.
A PDF that already has a password or restrictions is not accepted, because its existing protection would have to be removed first. If you know its password, unlock PDF removes it in your browser, and you can then protect the copy with a new one. To change the password of a file you protected here, keep the original and protect it again with the new password. To label a document as confidential without locking it, watermark PDF adds a visible text to every page instead.