保护PDF
为PDF添加密码保护
Drop your PDF file here
or click to browse
浏览器处理
文件在您的浏览器中本地处理
自动删除
处理后文件自动删除
无需注册
无需创建账户即可使用所有工具
随处可用
任何设备、任何浏览器，无需安装
如何保护PDF
上传PDF
选择或将您的PDF文件拖放到上传区域。
设置密码
输入一个强密码来保护您的文档。
应用
点击应用以使用密码保护加密您的PDF。
下载
下载受密码保护的PDF文件。
Why Password Protect PDFs?
Password protection adds security to sensitive documents. Whether you're sharing confidential business files or personal documents, encryption ensures only authorized people can access your content.
When to Use Password Protection
- Confidential Business Documents: Contracts, financial reports, and HR files.
- Personal Information: Tax documents, medical records, and identification copies.
- Intellectual Property: Drafts, proposals, and proprietary information.
- Client Deliverables: Protect work until final payment or approval.
Permission Levels
Beyond passwords, you can restrict specific actions: disable printing to prevent physical copies, disable copying to protect text, or disable editing to preserve document integrity. Combine restrictions for maximum security.
常见问题
How do I add a password to a PDF?
Upload your PDF, enter a password, choose which permissions to allow (printing, copying, editing), and click "Protect PDF" to encrypt your document.
What is the difference between user and owner password?
The user password is required to open the PDF. The owner password (optional) controls permissions like printing and copying, even after the PDF is opened.
Is this tool free to use?
Yes, our PDF protection tool is completely free with no registration required.
What permissions can I restrict?
You can restrict printing, copying text/images, editing content, adding annotations, filling forms, and extracting pages.
How strong is the encryption?
We use 128-bit AES encryption, which is industry standard and provides strong protection for your documents.
Can I password protect multiple PDFs at once?
Currently, you can protect one PDF at a time. For multiple files, repeat the process for each document, or merge them first and protect the combined file.
What makes a strong PDF password?
Use at least 12 characters combining uppercase, lowercase, numbers, and symbols. Avoid dictionary words and personal information.
Can I remove the password later?
Yes, if you know the password, use our Unlock PDF tool to remove protection. Without the password, the encryption cannot be bypassed.
Will recipients need special software to open it?
No, any standard PDF reader (Adobe Acrobat Reader, Preview, Chrome, Edge) can open password-protected PDFs. Recipients just need to enter the password.
Can I prevent printing but allow viewing?
Yes, you can set granular permissions. For example, allow viewing but disable printing, copying, and editing separately.