Is my file uploaded to your servers?

No. The whole process runs in your browser. Your PDF is read into memory, encrypted on your device, and handed straight back as a download. The file never leaves your computer and we never receive it.

What kind of encryption do you use?

AES-256, the same strong standard used to protect banking, government, and other sensitive documents. The password you choose is required to open the file in any standard PDF reader.

What happens if I forget the password?

There is no back door. Because the file is genuinely encrypted, nobody, including us, can open it without the password. Choose one you will remember, or store it somewhere safe.

Why do I need to sign in to download?

The protection itself is free and happens entirely in your browser. A free account is only needed to download the finished file, and signing in never sends us your document or your password.

Can I password protect a PDF that already has a password?

Not directly. A file that is already encrypted has to be opened first. Remove the existing password with our Unlock PDF tool, then set a new one here.

How do I remove the password later?

Open our Unlock PDF tool, upload the protected file, and enter the password. It saves an open copy you can use normally.

Password Protect PDF

Password protect a PDF with AES-256 encryption, right in your browser. Your file and your password never leave your device.

Set a password so only people who have it can open the file.
AES-256 encryption applied in your browser. Nothing is uploaded.
Free to use. Sign in to download your protected file.

Your PDF is encrypted right in your browser with AES-256. It never leaves your device, and we never see your file or your password.

Drag and drop a PDF hereOr click to choose a file. PDFs up to 100 MB.

Why Choose Us to Lock Your PDFs

Add a real password to a PDF without ever uploading the file or trusting a stranger with the key.

Password Protect a PDF Without Uploading It

Some documents are not meant for every set of eyes: a contract, a pay stub, a medical record, a tax return. Locking a PDF with a password means it will not open for anyone who does not have it, even if the file is forwarded, left on a shared drive, or attached to the wrong email. Our Lock PDF tool adds that password and encrypts the file with AES-256, the same standard trusted for sensitive data everywhere.

What makes this different is where it happens. The encryption runs entirely in your browser. Your file is never uploaded to our servers, and the password you choose never leaves your device. You get a protected copy back without ever handing the original, or the key to it, to anyone.

Strong Encryption, Simple Steps

Drop your PDF onto the box above, type a password, confirm it, and download the protected file. That is the whole process. There is nothing to install and no settings to wade through, and the AES-256 encryption we apply is the same grade used to protect banking and government documents.

Choose a password you will remember, or store it somewhere safe. Because the file is genuinely encrypted, not just flagged as restricted, there is no back door: anyone who opens the PDF later, including you, will need that password. If you ever need to take it back off, our Unlock PDF tool removes the password from a file you can already open.

Private by Design

Most online PDF tools upload your file to a server, process it there, and send a copy back. For a document you are locking precisely because it is sensitive, that round trip is exactly what you want to avoid. Lock PDF skips it by doing the work in your browser.

Your original file stays on your computer the whole time. We never receive it, never store it, and never see the password you set. There is nothing on our side to leak, and nothing for us to review, share, or train on.

When the job finishes, share the protected file however you like. The recipient is prompted for the password the moment they open it in any standard PDF reader.

Why Password Protect PDFs with PrintFriendly

Locking a PDF is the simplest way to keep a private document private. Our online tool encrypts the file in your browser in seconds, with no software to install.

Encrypted in Your Browser

The AES-256 encryption runs on your own device. Your file is never uploaded and your password is never transmitted, so there is nothing on our servers to expose.

Real AES-256 Protection

We apply genuine password encryption, not a cosmetic restriction. The file will not open in any reader without the password you set.

Fast and Simple

Drop a PDF, choose a password, and download the protected copy. No installs, no account needed to start, and it finishes in seconds on most files.

You Hold the Key

Only you know the password. We never see it and cannot recover it, so keep it somewhere safe. Need to remove it later? Use our Unlock PDF tool.

Frequently Asked Questions

Check out these commonly asked questions and answers about our service. Please feel free to contact us if you have any additional questions.

Is my file uploaded to your servers?
No. The whole process runs in your browser. Your PDF is read into memory, encrypted on your device, and handed straight back as a download. The file never leaves your computer and we never receive it.
What kind of encryption do you use?
AES-256, the same strong standard used to protect banking, government, and other sensitive documents. The password you choose is required to open the file in any standard PDF reader.
What happens if I forget the password?
There is no back door. Because the file is genuinely encrypted, nobody, including us, can open it without the password. Choose one you will remember, or store it somewhere safe.
Why do I need to sign in to download?
The protection itself is free and happens entirely in your browser. A free account is only needed to download the finished file, and signing in never sends us your document or your password.
Can I password protect a PDF that already has a password?
Not directly. A file that is already encrypted has to be opened first. Remove the existing password with our Unlock PDF tool, then set a new one here.
How do I remove the password later?
Open our Unlock PDF tool, upload the protected file, and enter the password. It saves an open copy you can use normally.