Rebuild a duplex document from two scan passes
A scanner with a single-sided automatic feeder can capture the front sides in one PDF and the back sides in another. Alternate & Mix PDF takes one page from File A, then one from File B, repeating until both stacks are combined into a single reading-order document.
Reverse the back-side scan when the stack was flipped
The second pass often arrives in reverse order. For example, a six-page document can produce File A as pages 1, 3 and 5 while File B contains pages 6, 4 and 2. Keep “Reverse File B” selected to produce 1, 2, 3, 4, 5, 6.
Preview the planned sequence before downloading
The sequence preview labels pages from File A and File B so you can confirm the direction and starting file. Swap the files, reverse either stack or start with File B when the first pass was loaded differently.
Mix more than one page per turn
Most duplex scans use one page from each file at a time. The pages-per-turn control also supports grouped material, such as taking two pages from File A followed by two pages from File B. When one file runs out, remaining pages from the other file are kept.
Check unexpectedly different page counts
Front and back scan files usually have equal page counts or differ by one when the final sheet has a blank side. A larger mismatch may be valid, but it can also indicate a missed page, scanner jam or double feed. FigureOwl warns you while still allowing the output.
Pages retain their original dimensions
Page content is copied without rasterizing or resizing it, so existing text and vector graphics remain sharp. Mixed Letter, A4, portrait and landscape pages keep their own sizes and orientations.
Understand page-copy limitations
The visible pages are copied into a new PDF. Document-level bookmarks, attachments, scripts, form relationships and portfolio structure may not survive. Combining pages changes the document and invalidates existing digital signatures, so retain the source files when those features matter.
Private processing on your device
Both PDFs are read and interleaved in browser memory. FigureOwl does not receive, store or inspect either file. Each source is limited to 200 pages and the pair must total 150 MB for reliable browser processing.