Lock a PDF with a password

An online tool to lock a PDF with a password and optional permission restrictions before you email it. Encryption is real PDF Standard Security V=5/R=6 AES-256 — the same standard Adobe Acrobat produces, opening cleanly in every PDF reader released since 2017 (Acrobat, Preview, Foxit, Edge, Chrome, mobile readers). Set whether viewers can copy text, print, or modify the document. Owner-password mode for advanced workflows where the open password and the permissions password differ.

How to password-protect a PDF

1
Upload your PDF

Drop the file or pick it from your device.

2
Set a password

Type it twice. Aim for 12+ chars with mixed case and digits.

3
Choose permissions

Decide whether copy, print, and modify are allowed.

4
Protect and download

A new encrypted PDF that requires the password to open.

Real AES-256 encryption — the same kind a desktop PDF editor produces

Drop a document here
PDF ·
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What you can do

AES-256 encryption
PDF Standard Security Handler V=5/R=6 — opens in every reader from 2017+.
Permission flags
Independently allow or deny copy, print, and modify.
Owner-password mode
Set a separate password for permission overrides.
Strength meter
Live feedback on password length, character mix, and entropy.
Confirm field
Prevents typos. The password you can't recover is the password you mistyped.
Works on any device
Phone, tablet, desktop — no installation, no signup, no per-file size cap.

Common uses

  • Lock a payslip or tax return before emailing it.
  • Distribute a contract with copy-prevention so excerpts can't be quoted out of context.
  • Ship a print-disabled review PDF to limit reproduction.
  • Pre-share invoices with clients using a shared client-specific password.

Why protect here

Real AES-256 encryption — the same Standard Security handler Acrobat writes — plus separate copy, print and edit permissions.

Frequently asked questions

Is the encryption real?

Yes. AES-256 PDF Standard Security V=5/R=6. The encryption is in the file itself, not a viewer hint.

Can the password be recovered if I forget it?

No. AES-256 is computationally infeasible to brute-force. Write it down somewhere safe.

What if my PDF is already encrypted?

Remove the existing password first with the Unlock tool, then return here.

Does the PDF still open in every reader?

Yes — every PDF reader released since 2017 supports AES-256 (PDF spec extension level 8).

Owner password vs user password?

User (open) password is required to view. Owner password overrides permission restrictions only. We default both to the same value; advanced mode separates them.

Mobile?

Yes. iOS and Android browsers work. First run loads the encryption engine (~1.3 MB), cached after for instant re-use.

Does this block screenshots or "Save As" workarounds?

No — and no PDF encryption can. AES-256 stops someone without the password from opening the file at all; once a viewer has decrypted it for display, screenshots and OCR are physically possible. The "no copy / no print" flags discourage casual reuse but a determined viewer can always rasterise. For real distribution control look at DRM systems (Adobe DRM, Vitrium) — a fundamentally different category of product.

Can I send a protected PDF by Gmail or Outlook?

Yes — the encrypted file is just a normal PDF. Standard attachment limits apply (Gmail 25 MB, Outlook 20 MB, most business mail 10 MB). Encryption itself adds only a few kilobytes.

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Who is this tool for?
✨ Content Creators 🎓 Students 🔒 Security & Privacy
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