Merge Order

PDFs merge in alphabetical filename order. There is no drag-and-drop reordering in the app — the order is determined entirely by the filenames in your folder.

How alphabetical order works

Files are sorted by filename including the extension, using standard ASCII/Unicode alphabetical ordering. Numbers come before letters, and 0–9 sort before A–Z.

This means you can control sequence precisely by prefixing filenames with numbers:

00_cover.pdf
01_introduction.pdf
02_chapter-one.pdf
03_chapter-two.pdf
04_chapter-three.pdf
98_bibliography.pdf
99_back-cover.pdf

Tips for consistent ordering

  • Use zero-padded numbers — 01, 02, 03 rather than 1, 2, 3. Without padding, 10 sorts before 2 alphabetically.
  • Leave gaps — number in steps of 5 or 10 (05, 10, 15) so you can insert files later without renaming everything.
  • Keep names consistent — avoid mixing uppercase and lowercase at the start of names, as case affects sort order on some systems.

Example: book layout

A typical book folder might look like:

00_cover.pdf
01_title-page.pdf
02_copyright.pdf
03_table-of-contents.pdf
10_chapter-1.pdf
20_chapter-2.pdf
30_chapter-3.pdf
90_appendix.pdf
99_back-cover.pdf

The output file would be named after the folder — for example, if the folder is MyBook, the result is MyBook.pdf.