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PROTECT PDF

Protect PDF

Add a password and permissions to your PDF with real encryption

Drop your PDF here

Add a password and permissions to your PDF

PDF only · Max 100MB · Files stay private

  • Real Encryption

    We encrypt the PDF with AES-256 by default — not a fake lock screen.

  • Permission Controls

    Limit printing, copying, editing and more where the PDF standard supports it.

  • Output Verified

    Protected files are checked so the open password and encryption actually apply.

  • Private & Secure

    Passwords are never logged or stored. Uploads are deleted after retention.

How to Password Protect a PDF?

  1. 1

    Upload PDF

    Drag & drop or choose a PDF file.

  2. 2

    Set password

    Choose an open password and optional permissions password.

  3. 3

    Choose permissions

    Allow or restrict printing, copying, editing and more.

  4. 4

    Download

    Save your protected PDF. The original file stays unchanged.

Password protection that actually encrypts your PDF

OneFileKit encrypts your PDF with a real encryption standard (AES-256 by default) and applies the permission flags you select. This is not a cosmetic lock icon or a renamed file.

PDF permission restrictions depend on the reader or application that opens the file. They are not a guarantee against every possible form of copying or access. An open password provides stronger protection for viewing.

If a PDF is already encrypted, we will not silently overwrite its security. You must supply the current password when reconfiguration is allowed.

Security & privacy

  • Uploads are validated by extension, MIME type and PDF structure.
  • Passwords are kept only for the current processing operation — never in analytics, logs, URLs or long-term storage.
  • The original uploaded file is never overwritten.
  • Downloads require a secret token bound to your job.
  • Temporary files are deleted after the configured retention period.
  • Permission enforcement varies by PDF application; encryption of the open password is the stronger control.

Related PDF Tools

Frequently asked questions

Is the PDF really encrypted?
Yes. We apply real PDF encryption (AES-256 by default) and verify that the protected file requires the open password when you enabled that option.
Do permissions stop all copying?
No. Permission flags are enforced by many PDF readers, but they are not a cryptographic guarantee against every application. Use an open password for stronger protection.
Can I protect a PDF that already has a password?
Only if you provide the current password so we can authorize reconfiguration. We never guess or brute-force passwords.
Is my original PDF changed?
No. Protect creates a new file. Your original upload remains unchanged and is deleted after retention.