Separate file order from page order
Merging copies all pages of each selected PDF. If A has two pages and B has three, A then B should produce A1, A2, B1, B2, B3. This is different from selecting individual pages. A page-range field or a move-up button is not part of this Merge PDF screen. Use the separate page-organizing tool if you need to rearrange individual pages after merging.
Select and read the current list
Keep both originals. Open Merge PDF and select Choose files. Select the PDFs together in the file chooser. Before selecting Create result, read the filenames in the displayed card sequence, starting with the first card. Selecting files again replaces the current selection; it is not a reliable way to append another document. If the list is wrong, use Reset and select the intended set again, then inspect the cards again. Numbered names such as 01-cover.pdf and 02-appendix.pdf can help you recognize the desired order, but never assume filenames alone determine the output.
A two-file example with an unmistakable boundary
We created two synthetic one-page PDFs: 01-cover.pdf visibly says A - COVER on blue, and 02-appendix.pdf says B - APPENDIX on orange. Selecting B then A showed that order in the file cards; the downloaded two-page file opened as B then A. After a new selection showing A then B, the second download opened as A then B. Independent PDF text extraction and page rendering confirmed both orders. This checks the boundary that is easy to miss when the source documents look alike.
| Input | Output |
|---|---|
02-appendix.pdf → 01-cover.pdf | B - APPENDIX → A - COVER · 2 |
01-cover.pdf → 02-appendix.pdf | A - COVER → B - APPENDIX · 2 |
Create, download and reopen
When the visible list is correct, select Create result and wait for Download: merged.pdf. Save it under a name that will not overwrite an original. Open the download in a PDF viewer. Count the pages, read the first page and inspect the last page of one source followed by the first page of the next. If the order is wrong, return to the list and create a fresh result after correcting the selection. Checking a card preview alone is not checking the exported file.
If ordering or loading fails
The page describes dragging file cards to reorder them, but our automated pointer drag did not change the order. We therefore do not claim that drag succeeded in this test. Use a visibly verified selection order rather than trusting an unresponsive gesture, especially on a touch device. If a source is encrypted or unreadable, use a readable unencrypted copy you are entitled to process. Large files can exhaust browser memory. Stop after a failed export and preserve the originals rather than accepting an incomplete result.
Frequently asked questions
Does the merger sort files by name?
Do not assume so. The visible card order is the relevant order to verify.
Can I merge only page 3 from a source?
This workflow copies whole PDFs. Use Extract PDF pages first if appropriate.
Can I trust a successful download without opening it?
No. Verify page count and source-file boundaries in the saved PDF.
Limits
The example proves ordinary two-file page order and reopening, not preservation of digital signatures, forms, bookmarks or every PDF feature. Physical touch dragging remains UNKNOWN.