iGuardPDF

Password Protect PDF

Lock a PDF with a real password — genuine AES-256 encryption, not a cosmetic lock. Free, no signup. If you lose the password, there is no recovery — that's what makes it real encryption. Read more about protecting confidential PDFs.

This is just the start — Pro also gets you, from £4/month

  • Invisible fingerprinting on every document
  • Share links for Guarded documents
  • Photo verification on open — approve or deny in 60 seconds
  • View-only mode — no download on shared links
  • Revoke access instantly, even after it's been opened
  • Burn-after-read — set a view limit or expiry date
  • Geofencing — restrict who can open it by country
  • One-click legal evidence export if a leak needs to be traced
  • Document analytics — views, shares, countries, and timestamps for every document you send
  • Real-time alerts the moment someone copies, screenshots, or opens on a new device
  • Tracking beacon — get pinged the moment a document is opened in Adobe Acrobat/Reader, even offline
  • Auto-lock on copy or screenshot attempt — the share link revokes itself the instant one is detected
See everything Pro unlocks — £4/month →

How to password-protect a PDF

  1. Upload the PDF you want to lock.
  2. Set a password.
  3. Download the encrypted file — it can't be opened without that password.

Common reasons to password-protect a PDF

  • Sending a sensitive document by email, with the password shared separately
  • Protecting a file stored on a shared drive
  • Locking a document before handing over a device or USB drive

FAQ

Is this real encryption, or just a PDF viewer restriction?

Real AES-256 encryption — the file genuinely cannot be opened without the password, not a soft permission flag some readers ignore.

What happens if I forget the password?

There's no recovery. The encryption is real, so losing the password means losing access — keep it somewhere safe.

Can I remove the password later?

Yes, with the Unlock PDF tool, if you still have the password.