合并 PDF 文件
按您选择的顺序，将两个或更多 PDF 合并为一个文件。
使用方法
添加您的 PDF 文件，拖动调整顺序，然后合并。合并后的文件会立即下载——整个过程都不会上传到服务器。
真的免费吗？
是的——没有每日限制，没有文件大小上限，也无需注册。既然没有服务器成本需要收回，自然也就无从收费。
我可以合并的 PDF 数量有限制吗？
没有——您可以添加任意数量的文件。一切都在您的浏览器中运行，唯一的限制是您设备的内存，而不是我们设置的上限。
合并前我可以重新排序吗？
可以——合并前，您可以拖动缩略图或使用箭头按钮将文件排列成所需的顺序。
Do the merged files need to be the same page size?
No — pages keep their original size and orientation. A mix of A4, Letter, and even landscape pages will merge fine; each page in the output keeps its own dimensions.
Does merging affect bookmarks or metadata?
The merged file is built fresh from the pages of your source files, so existing bookmarks and per-file metadata (like author or title) from the originals aren't carried over. Use Edit PDF Metadata or Create PDF Bookmarks afterward if you need those.
Can I merge very large PDF files?
Yes — there's no file size cap imposed by the tool, since merging happens on your own device instead of a server with an upload limit. Very large files (hundreds of megabytes, or documents with thousands of pages) will simply take longer and use more of your browser's memory; the ceiling is your device, not a rule we set.
How this is different from Adobe, Smallpdf, or iLovePDF
Those tools merge your PDFs on their own servers — upload, process, download, then delete the file after a set window (an hour, a day). That's a real privacy practice, but it still means your file left your device at some point. FatafatPDF's merge runs entirely with WebAssembly in your browser tab: there's no upload step to encrypt or delete later, because the file never leaves your device in the first place. No account, no file-count cap, and no Pro-tier upsell for larger jobs either — those are the limits competitors add to push you toward a paid plan.
Is it safe to merge PDFs online?
With most online mergers, "safe" means uploaded over an encrypted connection and deleted after some window — an hour, a day. Your file still left your device and sat on someone's server in between. FatafatPDF skips that step entirely: the merge runs with WebAssembly in your browser tab, so there's no upload to secure and nothing to delete later, because nothing was ever sent anywhere. Open DevTools → Network tab while merging and you'll see it yourself.
Can I merge PDFs on my phone — iPhone or Android?
Yes. The same browser-based tool works on mobile Safari and Chrome — tap to browse, pick your files from Files, iCloud Drive, or your device storage, reorder them, and merge. No app to install either way.
Can I merge a password-protected PDF?
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