📚 PDF 合并Merge PDF
把多个 PDF 合并成一个文件：拖入文件后可上下调整顺序、按文件名排序、只取每个文件的部分页码，也支持输入密码合并加密 PDF，全程在浏览器本地完成。Combine several PDFs into one — reorder files, sort by name, take only selected pages from each file, and merge password-protected PDFs after unlocking them. Everything happens locally in your browser.
使用说明与常见问题How-to & FAQ
「PDF 合并」是什么？What is the Merge PDF tool?
把多个 PDF 合并成一个文件：拖入文件后可上下调整顺序、按文件名排序、只取每个文件的部分页码，也支持输入密码合并加密 PDF，全程在浏览器本地完成。Combine several PDFs into one — reorder files, sort by name, take only selected pages from each file, and merge password-protected PDFs after unlocking them. Everything happens locally in your browser.
如何使用「PDF 合并」？How do I use the Merge PDF tool?
在「PDF 合并」中，点击「合并 PDF」、「按文件名排序」、「清空列表」按钮即可。支持拖放文件。Click "Merge PDFs", "Sort by name", "Clear list". Drag-and-drop files is supported.
合并后的页面顺序是怎样的？What order are pages merged in?
按列表从上到下的顺序依次拼接，每个文件内部保持原页序；可用 ↑ ↓ 调整文件顺序，或点击“按文件名排序”（自然排序，2 排在 10 前面）。Files are joined top to bottom in list order, keeping each file's own page order. Use ↑ ↓ to reorder, or Sort by name (natural order, so 2 comes before 10).
可以只合并某些页吗？Can I merge only some pages?
可以。在每个文件后的输入框里填写页码范围（如 1-3,5），留空则合并全部页面；也可以写成 3,1,2 改变该文件内的页序。Yes. Enter a page range (e.g. 1-3,5) next to each file; leave it empty for all pages. Writing 3,1,2 also reorders pages within that file.
会保留书签、链接和表单吗？Are bookmarks, links and forms kept?
页面内容、批注和链接外观会保留；原文件的书签（目录大纲）不会合并到新文件中，指向其他页面的内部链接可能失效，同名表单字段可能冲突。Page content, annotations and link appearances are kept. Bookmarks (outlines) are not carried over, internal links to other pages may break, and form fields with the same name may conflict.
加密的 PDF 可以处理吗？Can it handle password-protected PDFs?
可以。如果 PDF 需要打开密码，会提示你输入；只有权限限制（无打开密码）的文件会自动打开。输出文件不再带密码，如需加密请使用“PDF 加密”工具。Yes. If the PDF needs an open password you'll be asked for it; files with only permission restrictions open automatically. The output is not password-protected — use the Protect PDF tool if needed.
文件会上传到服务器吗？Are my files uploaded?
不会。PDF 在你的浏览器里用 pdf-lib / pdf.js 处理，文件不会离开你的设备，关闭页面后不留存任何数据。No. The PDF is processed in your browser with pdf-lib / pdf.js; files never leave your device and nothing is kept after you close the page.
「PDF 合并」免费吗？需要注册吗？Is the Merge PDF free? Do I need an account?
「PDF 合并」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Merge PDF is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.