How to use Alternate & mix
- Add the PDF with the front sides, then the one with the back sides.
- Tick the box if the back sides were scanned in reverse.
- Press Mix pages and download the combined PDF.
Double-sided scanning on a one-sided scanner
If your scanner only scans one side, scan all the front sides first, then flip the stack and scan the back sides. You'll have two PDFs. Alternate & mix puts them together in the right order: front 1, back 1, front 2, back 2 and so on. If you flipped the stack, the back sides come out last page first, and one tick fixes that.
Private by design
Alternate & mix runs entirely in your browser. Your file is processed on your own device and is never uploaded to a server, there's no sign-up, and the result is ready to download as soon as it's done.
Questions
What if the two files have different page counts?
Pages are mixed while both files have pages, then the remaining pages of the longer file are added at the end.
What does the reverse option do?
It flips the order of the second file before mixing, which is what you need when the back sides were scanned last page first.
Can I mix more than two files?
Mix two at a time. Then mix the result with the next file.