Input order
First sequence supplies odd-positioned output pages.
Confirm which scan holds fronts before starting.Interleave PDFs
Alternate pages from two documents to assemble a front-and-back scan or combine corresponding records. Reverse the second sequence when needed.
Drop your PDF files here
Start with at least 2 files. You can add more later.
Files stay on your device No sign-up Free to use
How it works
Identify fronts and backs
Add the first sequence, then the second.
Correct the second scan direction
Enable reverse second file if the backs were scanned in reverse order.
Verify paired physical sheets
Interleave and verify the resulting page sequence.
Interleave PDFs
Organize
Alternate pages from two PDFs, useful for duplex scans
Assemble separate front and back scans
Four sheet fronts are scanned into A, while the back scan B runs from sheet 4 to sheet 1. Add A first and B second, enable reverse second file, then check output as A1, B4, A2, B3, A3, B2, A4, B1 against the physical sheets.
✓ Compare output sequence with physical sheets: front 1, back 1, front 2, back 2. Output count should equal both input counts added together.Make it work for your document
Options after selecting a fileReverse second file
Reverse the second sequence before alternating.
Use only when the backs were scanned in the opposite order.Frequently asked questions
The details, when you need them.
What happens when the page counts differ?
The remaining pages from the longer file are appended.
Can I alternate more than two files?
This tool takes two sequences. Use Organize PDF for a more complex arrangement.
Assemble two-sided scans
A common workflow scans the front sides into one file and the back sides into another. The output alternates first-file page 1, second-file page 1 and so on. If the second scan starts with the last back side, reverse it before alternating. Check a small sample to confirm the scanner’s ordering.
Handle different page counts
When one file has more pages, the remaining pages are appended in their existing sequence. No pages are silently discarded. This tool does not detect missing backs or insert compensating blanks automatically. Use Organize PDF afterward if a physical sheet was missing from either scan.
Check the saved result
Compare output sequence with physical sheets: front 1, back 1, front 2, back 2. Output count should equal both input counts added together.
Missing sides are not automatically detected
Remaining pages from a longer input are appended. Missing backs are not detected and compensating blanks are not inserted.
Fronts and backs stop matching halfway through
A side may be missing, making automatic alternation unsuitable. Use Organize PDF to insert a blank or correct the sequence.