Alternate Merge
Merge two PDFs by alternating pages. Perfect for fixing duplex scans (front and back) into a single, correctly ordered document. 100% private.
Upload PDF Files
About This Tool
Alternate Merge is the ultimate solution for users with non-duplex scanners. If you've scanned the front sides of a stack of papers into one PDF and the back sides into another, this tool perfectly interleaves them into a single, coherent document.
Beyond simple merging, it features advanced logic to handle "reverse order" scans. If your scanner processed the back pages in reverse sequence, simply toggle the reverse option to restore the natural flow of your document. It's like a digital "shuffler" that saves hours of manual page reordering.
Security at its Core: Since your documents never leave your local machine, this tool is ideal for sensitive contracts, legal briefs, and personal records that require absolute confidentiality.
How to Use
Upload Two PDFs
Upload the front pages PDF and back pages PDF.
Configure Order
Choose whether to reverse the second document for back-to-front scans.
Merge and Download
Click Merge to interleave pages and download.
Use Cases
Duplex Scanning
Combine separately scanned front and back pages.
Document Assembly
Interleave pages from two related documents.
Book Scanning
Combine odd and even page scans into complete books.
Frequently Asked Questions
What happens if the two PDFs have different page counts?
The tool will continue alternating until the shorter document ends, then it will append all remaining pages from the longer document to the end.
Can I reverse the back pages only?
Yes, you can choose to reverse either the first or second document. This is common when scanners stack back pages in the opposite order.
Is this process secure for legal documents?
Absolutely. The merge is performed entirely in your browser using JavaScript. No document data is ever uploaded to a server.