Protect PDF documents with a password easily

Password protect your PDF to prevent unwanted access. Keep your files safe and sensitive info secure with a free online PDF lock with trusted encryption.

首先上載以密碼加密的PDF檔案。如果你的檔案沒有被高度加密，它將在數秒鐘內解密並供你下載。 安全地處理你的資訊. 在上載檔案時，我們採用安全的連接模式傳送檔案資料。

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.

Free online tool to password protect PDF files and to set PDF security settings. No quality loss. Without installation. Without registration.

Upload PDF file to protect with a password using 256-bit AES encryption. · Enter a strong password to lock your PDF document. Set viewing and editing permissions ...

Protect PDF is a free online tool to secure PDF and set various permissions such as copying, printing, and modification. If you are looking to encrypt PDF, lock ...

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

Remove PDF password online. Remove security from password protected PDF files.

免費的在線PDF加密工具，只需上傳PDF, 即可為PDF設置打開密碼和許可權密碼，限制用戶拷貝，列印等操作，安全可靠，保護您的PDF文件。完全免費，不需要註冊會員， ...