将多个 PDF 文件合并为一个——免费

Drop two or more PDFs onto the tool, drag the rows to set the merge order, and click Merge & Download. Pages from each source PDF are copied into a single output document in your chosen order. Your files are uploaded over HTTPS and merged on our secure server, then automatically deleted afterward.

你可以对整个文件重新排序（上下拖动对应的行），也可以用垃圾桶图标将某个文件从合并中移除。如需对 PDF 内的单页重新排序，请先用我们的「整理 PDF」工具处理，然后再合并。

Page content (text, images, fonts, hyperlinks within a page) is preserved exactly because whole pages are copied atomically rather than re-rendered. Document-level bookmarks and the table-of-contents are reset since the new file is a fresh document — re-add bookmarks with a desktop PDF editor if needed.

免费计划中的每个文件最大为 20MB，高级计划中的每个文件最大为 50MB，专业版中的每个文件最大为 120MB，并且您一次最多可以合并 20 个 PDF。在实践中，合并几本大型书籍（每本 500 多页）或数百份小型报告可以在该限制内轻松完成。

Yes — your PDFs are uploaded over an encrypted (HTTPS) connection, merged on our secure server, and automatically deleted afterward; we never store or share them. If your policy strictly forbids any upload at all (e.g. some compliance workflows for contracts, NDAs or medical records), use a desktop PDF tool that runs fully offline instead.

If you know the password, decrypt first with our PDF Password tool, then merge. The merge tool can usually handle PDFs with light protection, but PDFs with strict encryption (printing/copying disabled) need to be unlocked first.

会略小一些，因为合并过程中会对重复的字体和嵌入资源进行去重。差异通常只有几个百分点——只有在合并许多共用同一字体集的文件时（例如整套品牌报告系列）才比较明显。

Preview the merged PDF before signup, then create a free account for the standard download. Signed-in free allowances and file limits apply; Premium adds larger files and batch capabilities.

Yes — each page keeps its own dimensions in the combined file because pages are copied as-is rather than reflowed. An A4 contract, a Letter-size invoice and a landscape spreadsheet can all sit in one PDF, each at its original size. Drag the rows to control which document comes first.

可以，但要用别的工具：「拆分 PDF」会把一段页码范围（如 5-12）提取为单独的文件，而「整理 PDF」可让你删除或重新排列合并后结果中的页面。合并只负责把文件拼到一起，所以当你需要再次把合并后的 PDF 拆开时，请使用这些配套工具。

可以——在合并之前随时点击“添加更多”；新文件会追加到列表末尾，并自动渲染各自的缩略图。通过拖拽或使用上下箭头按钮，将它们相对于已有文件排到合适的位置——无需从头重新排序。

可以——每个文件行在拖动手柄旁都有小的上下箭头按钮，每次移动一个位置，这比在触摸屏上做拖动手势可靠得多。反复点按即可把文件一步步移到合并顺序的顶部或底部。

Yes — no desktop software is needed. Drop your PDFs into the browser, reorder them and preview the merge before signup. Create a free account to download the standard combined file without a watermark. Temporary files are processed over HTTPS and deleted automatically.