What encryption does this tool use?

It applies 256-bit AES encryption, an industry-standard level of protection widely used for sensitive documents.

Will the password protect the file everywhere it is sent?

Yes — the password requirement is embedded in the file itself, so it applies no matter where the file is opened or how it was delivered.

What happens if I forget the password?

The document cannot be opened by anyone, including us — we do not store passwords, so there is no recovery option. Keep your password somewhere safe.

Is an online tool as good as desktop software for this?

For this kind of task, yes — the underlying processing is the same; the difference is just that nothing needs to be installed.

Do I need an internet connection to use the online tool?

Yes — since processing happens on our server, you'll need an active connection to upload your file and download the result.

Security

Protect PDF Online

Doing this online, rather than with installed desktop software, means there's nothing to download, nothing to keep updated, and no license to buy. My PDF processes your file on a secure server and hands the result back in your browser, the same way whether you're on a desktop, laptop, tablet or phone.

Use the Protect PDF Tool

No registration required
Files deleted automatically
Works in any browser

Why This Matters

What Is a PDF Password Protection Tool?

A PDF password protection tool encrypts a document so that it can only be opened by someone who knows the password you set, using industry-standard 256-bit encryption. Once protected, the file itself — not just a viewer's settings — enforces the password requirement, so it stays protected no matter where the file is copied, emailed or stored.

Step by Step

How to Protect PDF Online

Upload Your PDF

Drag in the PDF you want to protect, or click to browse and select it.

Choose a Password

Enter and confirm a password of at least 4 characters — choose something memorable but not easily guessed.

Click Protect PDF

Our server encrypts the document with 256-bit encryption, typically within seconds.

Download the Protected File

Save your encrypted PDF, then share the password with your recipient through a separate channel.

Recommended Tool: Protect PDF

Add a password to keep sensitive files private.

Open Protect PDF

Get Better Results

Tips

Share the Password Separately — Send the protected PDF and its password through two different channels — for example, email the file and text the password.
Choose a Password You Will Remember — A password that only you can recall is safer, but a lost password means the document is permanently inaccessible — write it down somewhere secure.
An online tool updates itself — you are always using the current version, with no update prompts to click through.
Because everything happens in the browser, there's nothing left behind on your device afterward, unlike an installed application.

Avoid These

Common Mistakes

Uploading a file that is already password-protected without unlocking it first — most operations require an unencrypted starting file.
Assuming a converted or compressed file replaces the need for the original — keep your source file until you have confirmed the result looks right.
Not checking the 50 MB upload size limit before starting, then wondering why a very large scan fails to upload.
Assuming an online tool must be less capable than desktop software — for a task like this, the actual output is identical.