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Protect PDF

Encrypt your PDF with a password (AES-256). Nobody can open it without the password. Free, no sign-up — files are processed in your browser and never uploaded.

Drop your file here

or choose from your device

Protect PDF with Password Online Free

Lock a PDF with a password using strong AES-256 encryption. Files are processed in your browser and never uploaded.

How to use Protect PDF

  1. 1Open pdfhai Protect PDF and choose your file (or drag and drop it).
  2. 2Adjust the options if you need to — everything runs instantly in your browser.
  3. 3Download the result. No sign-up, no watermark, and your file is never uploaded.

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