How do I add a password to a PDF online?

Upload your PDF to One Free PDF, enter your desired password, then click 'Protect PDF'. Your encrypted PDF will download immediately. No signup required.

What encryption standard does One Free PDF use?

We use 128-bit AES encryption, the same standard trusted by banks and governments, to secure your PDF files with a password.

Can I set different passwords for opening and editing?

Yes. You can set a document-open password and separately restrict editing, copying, or printing with a permissions password.

Is it safe to protect a PDF online?

Yes. Your files are processed locally in your browser and never stored on our servers. The encrypted PDF is created client-side before being delivered to you.

Can I remove the password from a PDF later?

Yes. If you know the password, you can use a PDF unlock tool to remove password protection. One Free PDF does not store any passwords.

Protect PDF

Add a secure password to your PDF document to prevent unauthorized access.

or drag and drop your PDF file here

Why Use Our PDF Protector?

Experience the fastest, most secure way to add password protection to your PDF files.

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⚡ Lightning Fast

Encrypt and protect your PDFs in seconds. Our optimized engine delivers instant results.

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🔒 100% Secure

Your files are processed locally in your browser. Complete privacy guaranteed - we never upload or store your data or passwords.

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✨ Strong Encryption

We use advanced encryption standards to ensure your sensitive documents remain completely private.

The Best Way to Protect PDF Files Online

Add strong password protection to your sensitive PDF documents. Prevent unauthorized access, copying, or printing of your private files instantly and for free.

How to Use This Tool

Upload your PDF

Click 'Select PDF files' or drag and drop your confidential document into the upload area.

Enter a password

Type in a strong, memorable password that will be required to open the document.

Encrypt and Download

Click 'Protect PDF' to instantly encrypt your file, then download the secured document.

Key Features

Strong password encryption

Prevent unauthorized access

100% Free - No hidden costs

Secure browser-based processing

Passwords are never stored

Got Questions?

Protect PDF FAQ

Find answers to common questions about our PDF protection tool. Still need help? We're here to assist you.

Yes, all our PDF tools are 100% free to use. You can convert, compress, merge, or split PDFs without any hidden charges or sign-ups.