Decrypt PDFs

If you deal with encrypted PDF files, you need this!

Bulk-remove password protection from PDFs, right from Windows Explorer - and it learns your passwords so it gets faster every time.

🤔 Why I built this

Banks, brokers, insurance, and utilities send a lot of password-protected PDFs via email or web download, and every time I spend time working out the correct password - guessing the password, getting it wrong, trying again. Now I just point this at the Download folder and everything decrypts itself.

🔒 How is it secured

• Gated access: re-confirm your Windows login (password, PIN, or Hello) to open the Password Manager.
• Local only: no cloud sync, no telemetry, no network calls - only to your windows user login.
• Encrypted at rest: Windows DPAPI, tied to your Windows login only.
• Masked by default: passwords show as ******** until you reveal them.
• No admin rights needed: installer writes to your user registry hive only.

Caution

Only use this on PDFs you have the legal right to access - your own documents.

⚡ Features

• Bulk scan: a folder (recursive optional) or a batch of selected files.
• Auto-decrypt: tries every learned password, most-likely-first, no prompts.
• Password Manager: encrypted, masked, gated - see above.
• Flexible output: overwrite in place, or write out with a prefix/suffix.
• Live progress: status bar shows what's happening; press S to stop anytime.

🔁 How it learns and auto-decrypts

1. Type a password once - if it works, it's saved automatically.
2. Next scan, every stored password gets tried, most-successful-first.
3. First match wins - decrypts and moves to the next file.

🖥️ Requirements

• Windows
• .NET 8 Desktop Runtime (framework-dependent build)

📦 Installation

Option 1: Installer (recommended)

1. Download DecryptPDFs-Setup-<version>.exe from Releases and run it.
2. Installs to your own user folder - no admin rights, no UAC prompt.
3. Choose whether to add the right-click menu and/or "Send to" entry.

Also submitted to winget (pending approval) - once merged, winget install rukpat.DecryptPDFs will work directly.

Tip

Windows SmartScreen may warn about an "unrecognized publisher" since the installer isn't code-signed - click More info → Run anyway. Normal for any small, unsigned tool.

Note

What gets installed:

• Files to %LocalAppData%\Programs\DecryptPDFs
• Two HKEY_CURRENT_USER\...\shell\DecryptPDFs registry keys (context menu)
• A shortcut in shell:sendto (if selected)

Uninstall anytime from Add/Remove Programs - cleans up all of the above.

Option 2: Manual

Prefer to see exactly what's added before running anything? Do it by hand instead:

git clone https://github.com/rukpat/DecryptPDFs.git
cd DecryptPDFs
dotnet build

• Edit and import ContextMenuFiles.reg / ContextMenuDirectories.reg for the right-click menu (points at wherever you place DecryptPDFs.exe).
• Edit and copy Decrypt PDFs.lnk into shell:sendto for the Send to menu.

▶️ Usage

1. Right-click a folder or a selection of PDFs → Decrypt PDFs (or launch from the Start Menu and click Open PDF Files...).
2. Anything already known gets decrypted automatically; for the rest, type a password and hit Decrypt.
3. Open Password Manager anytime to review or edit stored passwords.

Important

License: MIT

Contributions: bug reports, feature requests, and PRs welcome.