Alternate & Mix PDF Pages
Interleave two PDFs — perfect for front/back scans.
Runs in your browser
Scanned a double-sided document on a single-sided scanner? Interleave the odd and even pages of two PDFs into one correctly ordered file on your phone or computer, without uploading anything.
How to interleave two PDF files
- 1Select two PDFs: the fronts file and the backs file.
- 2Drag to set their order, and keep the reverse option on if the backs were scanned last to first.
- 3Press the alternate & mix button.
- 4Download the correctly ordered PDF.
Why Sahl PDF?
- Fixes double-sided documents scanned on a single-sided scanner
- Reverse-second-file option is on by default for back scans
- Processed in your browser — no upload
- Works on computers and phones, nothing to install
Frequently asked questions
When do I need to alternate and mix?
When you scan all the front sides into one file and all the back sides into another. The tool puts the pages back in reading order.
Why reverse the second file?
When you flip a stack to scan the backs, they come out last page first. The reverse option fixes that automatically.
Can I use more than two files?
No, this tool takes exactly two files. To join several files end to end, use Merge PDF.
Is it safe?
Yes. The mixing happens in your browser and your files are never uploaded.
How do I merge odd and even pages into one PDF?
Put the odd pages (fronts) in the first file and the even pages (backs) in the second, then press alternate & mix to interleave them.
Can I alternate pages from two PDFs without signing up?
Yes. You can use it free 3 times a day with no account, and the files never leave your browser.