Merge Duplex Scans
FreeInterleave separately scanned front and back PDFs. Reverse the back pages when needed to restore the reading order.
Select PDF files to get started
Drag files here or choose them from your device
PDF · Up to 50 MiB each · Up to 2 files Files stay local. No uploads.Selected files
Arrange pages
Insert or replace pages
Insert before the target position. To append, enter the current page count + 1. Blank pages use the adjacent page size.
Replacement removes the same number of pages from the target position as the number of selected source pages. Source files are read locally.
Export in the displayed order. Labels show source files and page numbers. Inserted pages support selection, movement, rotation and undo.
Click a page to read it in detail. Use the checkboxes to select pages.
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How to use Merge Duplex Scans
- 01
Add the front PDF first and the back PDF second. Reorder the files if needed.
- 02
Choose whether to reverse the back pages based on the scan order.
- 03
Create a PDF with alternating front and back pages.
Frequently asked questions
Must both files have the same number of pages?+
Both files must have equal page counts, or the front PDF may have one extra page. The extra front page is kept at the end. Other differences stop processing.
When should I reverse the back pages?+
Reverse them when the back PDF starts with the back of the last sheet. Output becomes front 1, last back, front 2, second-to-last back, and so on.