Your files stay on your device

File processing runs in your browser. Documents are not uploaded to our servers. The site may download processing engines and send usage or feedback events without file contents.

How we handle your data

All PDF tools

Merge Odd and Even PDF Pages

Alternate PDF pages from two files to merge front and back scans into one ordered PDF, with an option to reverse the second. Free, no upload.

Choose files

or drag and drop them here · PDF

Two PDFs contain three labeled pages each. The output should contain six pages in the file order or alternating order you choose.

Your documents stay on this device. Tool downloads and usage statistics do not include file contents.

Local limits: Max total size: 60 MB

Files are processed in your browser. They are not uploaded to this site.

A practical guide

Create one checked, ordered scan file.

Choose exactly two PDFs, with the front-side scans first and the back-side scans second.
Choose Alternate, or Alternate and reverse the second file when its pages were scanned backwards.
Create the PDF and check the first, middle and last page pairs before continuing.

Try this example

Use fronts 1, 3, 5 and backs 6, 4, 2 as the two inputs. Reverse the second file so the output reads 1, 2, 3, 4, 5, 6, then inspect the sequence.

Before

Fronts 1,3,5
Backs 6,4,2

After

Input and expected output for this task. Illustrative example.

Before you start: This mode requires exactly two PDFs. If one file has extra pages, unmatched pages are appended at the end; confirm pairing and order yourself.

Review page order

Questions and answers

How do I merge front and back scans into one PDF?: Add the front scans first and the back scans second, set the mode to Alternate and create the PDF. Pages are taken one from each file in turn, so look at the first, middle and last pairs afterwards.
What if the back pages are in reverse order?: Keep Alternate and reverse the second file. Fronts 1, 3, 5 and backs 6, 4, 2 then read 1, 2, 3, 4, 5, 6.
What happens if one file has more pages than the other?: The extra pages go at the end. Check the pairing and the order before you send the file.
Can I merge more than two files this way?: No. This mode works with two PDFs only. To join several documents one after another, use Merge PDF.
Are my scans uploaded?: No. Your files stay on your device and are processed in your browser.

If it did not work

It says it needs exactly two PDFs: Select two files, not one or three. If the scan came out as many files, join the fronts into one file and the backs into another first.
It says the file is too big: Each PDF can be up to 10 MiB, with 200 pages in total, and the result can be up to 40 MiB. Compress or split the scans and merge them in parts.
It does not accept a password-protected PDF: Password-protected PDFs are not supported. Remove the password with Unlock PDF, then try again.
The pages are in the wrong order: Check that the fronts are in the first file and the backs in the second.
Bookmarks, form fields or signatures are missing: They are not guaranteed to be kept. Merge first, then add bookmarks, fill forms or sign the final copy.