Password Protect & Unlock PDF Online
Secure your PDF with a password, or remove password protection from an unlocked file.
- 256-bit encryption requested The processing engine is asked to protect the PDF with a 256-bit key.
- Unlock non-restricted PDFs Remove a known password from a file you have the right to open.
- 1 credit per use Uses your account's shared credit pool — 3 credits free to start.
Upload your file
Secure and privateDrop your PDF here, or browse
PDF files only
Security Settings
Max file size: 50 MB · Files deleted immediately after processing
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How to password protect a PDF online
- Upload the PDF you want to secure or open up.
- Choose Encrypt to add a password, or Decrypt to remove one you already know.
- Enter the password and press the button to process and download the file.
Why password protect a PDF
Email is forwarded, shared drives are broader than people assume, and laptops get lost. Encrypting payslips, medical letters, board papers or client records means the file is useless to anyone who ends up holding it without the password. The reverse is just as practical: once a document is filed internally, a password you have to look up every time is friction, so removing it from a copy you are entitled to open is often the sensible step.
About encryption and its limits
The app asks the processing engine to protect the document with a 256-bit key. We describe that as a request rather than a guarantee because the exact cipher and compatibility mode the engine selects are not surfaced here — worth testing if you must support an old reader. Two limits matter more day to day: this tool takes a single password, with no separate owner password and no per-permission controls for printing or copying, and there is no recovery path. If the password is lost the document may be unopenable, so store it somewhere safe. Changing encryption also modifies the file, which can invalidate an existing digital signature.
Frequently asked questions
- What encryption is requested when I password protect a PDF online?
- When you password protect a PDF online, the app asks the processing engine to use a 256-bit key. The exact cipher and compatibility mode are not exposed here, so test the protected PDF in any older reader you must support.
- Can PDFDW recover a forgotten PDF password?
- No. Unlocking requires the current password, and there is no password recovery or bypass feature. Keep a secure copy of any password you set because losing it may make the document inaccessible.
- Can I set separate owner passwords or printing permissions?
- No. This tool accepts one password and does not expose separate owner and user passwords or granular controls for printing, copying, editing, or form filling.
- Is the file uploaded, and what happens if processing fails?
- The PDF is uploaded for server-side protection or unlocking. A use costs one credit, which is refunded when processing fails. Changing encryption modifies the PDF and can invalidate an existing digital signature.