How it works
- 01Open the scan of the fronts.
- 02Open the scan of the backs — drop it onto the page.
- 03Check the order in the page rail; switch "Backs scanned in reverse" if the pairs are wrong.
- 04Export the combined document.
The reversed stack is the default
Turning a stack over means the last back is scanned first, so the second file arrives last page first. That is assumed unless you say otherwise, because it is what happens with nearly every sheet feeder. If your scanner or workflow keeps the backs in order, one switch changes it.
You can see the result before you export
Pages are only reordered — nothing is re-rendered or altered — so the page rail shows the combined order the moment the second file opens. Look at the first few pairs; if a front and back do not belong together, you will see it straight away rather than after printing.
When the two files are different lengths
A sheet that fed twice, or not at all, leaves one file a page longer than the other. The panel says so and by how many pages, and the unpaired pages are added at the end rather than dropped, so nothing is lost while you work out which sheet it was.
Keep editing in the same session
Once combined, the document is an ordinary set of pages: drag any of them, remove blank backs, rotate a sheet that went through upside down, then export once.
Questions
- Which file should I open first?
- The fronts, then the backs. If you opened them the other way round, choose "The second file opened" for page 1 instead of reopening anything.
- What if I open a third PDF?
- Only the first two files are alternated. Pages from any others are kept in their own order at the end, and the panel says so.
- Are my scans uploaded?
- No. Both files are opened and reordered by your own browser, and nothing is sent to a server.