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PDFSamurai

Security

Protect PDF.

Encrypt a PDF with a strong password so only people who know it can open the file. All encryption runs locally.

  • Runs in your browser
  • Never uploaded to a server
  • GDPR compliant

Drop a PDF to protect

or click to browse · processed in your browser · never uploaded

The password never leaves your browser. We can’t see it or recover it.

Add a password to a PDF

Password-protecting a PDF is one of the simplest forms of document security available. It is not unbreakable — no password is — but it does mean that someone who intercepts the file in transit, or finds it left on a shared drive, cannot casually open it.

Because this tool runs in your browser, the unprotected source PDF is never sent over the network. We apply 128-bit AES encryption to the document in memory and offer the protected version as a download. The password itself is typed only here, never transmitted.

Choosing a good password

  • Use a long passphrase, not a short complex string.
  • Avoid anything that appears elsewhere in the document.
  • Send the password through a different channel from the file itself.

Note: PDF encryption is supported by Acrobat, Preview, Chrome, Firefox, and every major mobile reader. Older command-line tools may need to be passed the password explicitly.

Questions

Frequently
asked.

  • Standard PDF AES-style encryption keyed to the password you provide. The password never leaves your device.

Related

More security tools.