Protect PDF Documents Online for FREE

Our online tool allows you to password protect PDF documents online for free
Drag & Drop the File(s) Here
Choose File

How It Works?

Upload your PDF

Select a PDF from your computer or cloud storage or just drag and drop a PDF into the box above

Easily Encrypt a PDF online

Password protect your PDF documents against unauthorized access. Allow only trusted recipients to open and edit your documents.

Protect PDFs in the Cloud

Our service allows you to encrypt PDF documents without having to install additional software to your computer. Save time protecting your documents online.

Absolutely Free

Forget about expensive software and time-consuming downloads. AltoProtectPDF allows you to protect PDFs online and absolutely for free.

Keep PDFs Secure

AltoProtectPDF keeps your PDF documents private. All documents are securely uploaded and processed. Once you’ve encrypted a PDF with a password and downloaded it, it will be deleted from our server.

Encrypt PDFs on any Platform

AltoProtectPDF is compatible with major operating system like Windows, Mac OS and Linux. You can easily password protect PDFs on any internet connected device in seconds.

How Do Users Rate AltoProtect?

Our service faciliates the work of over two million people protecting PDF documents online every year.


How to Protect PDF Files?

Do you need to quickly protect a PDF document? You don’t have to spend time searching for expensive software, downloading it to your computer and completing multiple installation steps. Use AltoProtectPDF to protect PDFs online quickly, easily and for free.

How to Protect a PDF Online

  • Drag and drop PDF files you want to protect from your computer or press the orange Choose Files button
  • Open a document in a PDF editor and click anywhere on a document to start typing. Change the font, size and color of your text in a single click.
  • When you’ve finished protecting your PDF, download your document.

AltoProtectPDF is the right solution if you need to urgently protect or annotate PDF contracts, agreements, invoices, medical or tax forms. Note that uploaded PDFs cannot exceed 25 MB.