Password Protect

Lock your PDF tight.

Set an open password and control what recipients can do — print, copy, or modify. Encryption happens entirely in your browser.

stays on this device

How it works

How to password-protect a PDF

  1. 1

    Open your PDF

    Click "Choose file" or drag your PDF into the tool. The file is loaded locally in your browser and never sent anywhere.

  2. 2

    Set your passwords and permissions

    Enter a user password (required to open the document) and an optional owner password to restrict printing, copying, or editing. Both are applied with 128-bit AES encryption.

  3. 3

    Download the protected PDF

    Click "Protect PDF" and download the encrypted file instantly. The original file is untouched; you get a new, locked copy ready to share.

PDFsuite encrypts your document entirely inside the browser using 128-bit AES, the same standard used by banks and government agencies. Because the file never leaves your device, there is no risk of interception during processing. The tool is free to use offline - just open it and your encryption happens locally, no internet connection required after the page loads.

You can set two separate passwords: a user password that recipients must enter to open the file, and an owner password that controls document permissions such as printing, copying text, and making edits. This dual-password model matches the PDF specification and is compatible with Adobe Acrobat, Preview on Mac, and every major PDF reader.

Protecting a PDF before emailing it is the single most effective step you can take to keep sensitive documents private. Whether you are sharing contracts, financial statements, or personal records, a strong password ensures that only the intended recipient can read the content. No cloud service stores your file, and no account is needed - just open, encrypt, and download.

FAQ

Common questions

Does the PDF get uploaded to a server when I protect it?
No. The entire encryption process runs in your browser using JavaScript and the pdf-lib library. Your file is never sent to any server, which means it stays completely private. You can even disconnect from the internet after the page loads and the tool will still work.
What encryption strength does PDFsuite use?
PDFsuite applies 128-bit AES encryption, which is the standard strength level specified in PDF 1.6 and later. It is the same algorithm used by most commercial PDF software and is considered secure for protecting sensitive business and personal documents.
Which PDF readers can open a password-protected PDF made here?
Any standard-compliant PDF reader can open the protected file, including Adobe Acrobat Reader, Apple Preview, Google Chrome, Mozilla Firefox, Foxit Reader, and PDF-XChange. The user simply enters the password when prompted - no special software is required.