Merge PDFs with Alternating Pages

Standard merging appends all pages from document B after all pages from document A. Alternating page merging interleaves them: A1, B1, A2, B2, A3, B3. The result reads as a parallel document where corresponding pages from each source appear consecutively. This is different from how most PDF merge tools work.

Select the two documents you want to interleave in Google Drive. Open the extension and switch to merge mode. Select the alternating pages option rather than the standard sequential merge. Confirm which document is A (odd positions) and which is B (even positions), then click Merge. The output interleaves their pages in order.

If document A has 10 pages and document B has 8 pages, alternating merging produces 18 pages where the last two pages are pages 9 and 10 from document A with no counterpart from document B. The extension appends the extra pages at the end rather than discarding them.

Duplex printing preparation is the most common use: scan one side of a document stack, then scan the reverse side, and use alternating merge to interleave them into the correct page order. Question-and-answer documents interleave questions from one Doc with answers from another. Bilingual documents place the English version of each page alongside the translated version.

Alternating merging puts corresponding pages on consecutive pages of the PDF. For a true side-by-side view on a single page (two columns), that requires a different tool that resizes and places pages next to each other on a wider canvas. Alternating merging keeps each page at its original size and alternates them.