保护 PDF
为您的 PDF 添加密码和权限限制。⚠ 此保护基于元数据（pdf-lib）。如需真正的 AES 加密，请使用专用工具，如 qpdf。
将 PDF 拖放到此处，或点击选择
PDF 最大支持 100 MB
为您的 PDF 添加密码和权限限制。⚠ 此保护基于元数据（pdf-lib）。如需真正的 AES 加密，请使用专用工具，如 qpdf。
将 PDF 拖放到此处，或点击选择
PDF 最大支持 100 MB
To protect PDF files with a password is to encrypt PDF content so that only people who hold the key can open it. The password acts as a key: without it the document stays unreadable, even if the file is intercepted or downloaded by mistake. It is the simplest way to secure a PDF before you let it travel.
Choosing to password protect PDF documents matters most for sensitive material: payslips, contracts, ID papers, medical records or bank statements. Think of it before emailing a file or uploading it to a shared drive, where several people might reach it. In those cases the password makes sure that only the intended recipient can read the information inside.
Pick a strong password that is long and unique, rather than an obvious word reused elsewhere. Share it through a separate channel from the file itself: if the PDF goes out by email, pass the key along by message or phone. Keep an unprotected original in a safe place too, so a forgotten password never locks you out. When you need to remove a password you already know, the unlock tool handles it, while watermark adds a visible CONFIDENTIAL mark and sign applies a signature.
Privacy stays at the heart of pdfOutils. No sign-up is required, and your files are deleted automatically after processing: they are never stored or reused. That way you keep full control of your documents and of the key that protects them.
Upload
Upload your PDF file into the drop area (or drag and drop it).
Configure
为您的 PDF 添加密码和权限限制。
Download
Download the resulting document in one click — your files are deleted automatically after processing.
Upload your PDF, choose a password and the permissions to restrict (printing, copying), then download the encrypted document.
The document is encrypted according to the PDF standard with an open password, compatible with all common PDF readers.
Yes. In addition to the open password, you can set permissions that restrict printing, copying text or editing the document.
The encryption is designed to be irreversible without the password, so we cannot recover it for you. Keep it somewhere safe, as a protected PDF with a lost password stays inaccessible.
Yes, this tool is 100% free with no usage limits. No sign-up, no credit card and no watermark added to your documents.
Yes. Your files are processed securely and automatically deleted from our servers after processing. Nobody has access to them.