Unlock PDF

Unlocking a PDF is easy with Smallpdf. You just need to upload your PDF, enter the password (for strongly encrypted files), and download the unlocked PDF!

No file size limits, no ad watermarks - A simple and secure web app to encrypt your PDF files with strong AES 128-bit encryption for free.

Password protect a PDF with an easy online tool. Protect sensitive content with trusted PDF encryption.

Encrypt PDF with open password and copying, printing permission. It's a free, secure and easy way to protect your PDF.

Encrypt your PDF files using 256-bit AES encryption to prevent anyone opening your PDFs without a password. There is no way to brute-force or reverse engineer ...

設置一個密碼來保護PDF文檔中的敏感資訊。輕鬆地線上保護你的PDF文檔，且無需註冊。

Encrypt and protect PDF with a password to safeguard sensitive information. Secure your PDF files online, with ease and without registration.

Protect your PDF files online by adding a password that will prevent people from being able to copy or print your PDF document. Secure PDF files for free.

No registration or watermarks. Simple and secure way to password protect your PDFs with strong AES 256 bits encryption.

Protect your PDF files by adding a password to those documents with our safe and easy-to-use online tool. Add permissions to your PDF files for FREE!