Merge PDF Files Online
Merge PDF documents directly in your browser. Reorder files, combine every page, and download one PDF without uploading documents to PrefillPDF.
Select PDF files
Drag and drop PDFs here, or choose from your computer.
Up to 20 files · 150 MB total
Help and answers
Frequently asked questions
Common questions about using the Merge PDF tool.
Are my PDF files uploaded to a server?+
No. The PDFs are read, merged, and downloaded inside your browser. PrefillPDF does not receive or store the files.
How many PDF files can I merge at once?+
You can merge up to 20 PDF files in one operation, with a combined size of up to 150 MB.
Can I change the PDF order before merging?+
Yes. Use the move controls beside each file to arrange the PDFs before creating the merged document.
Will merging reduce the quality of my PDF files?+
No intentional image recompression is applied. Existing PDF pages are copied into the merged document.
Can I merge password-protected PDF files?+
Password-protected files may fail to open unless they have already been unlocked. Remove the password first, then try merging again.
Can I merge PDFs in a specific order?+
Yes. The final PDF follows the exact order shown in the workspace, from top to bottom.
What happens to bookmarks and form fields after merging?+
Page content is preserved, but some advanced document structures such as bookmarks, embedded scripts, and interactive form behavior may not carry over exactly.
Does the original PDF get changed?+
No. The original files remain unchanged. PrefillPDF creates a new merged PDF for download.
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