How do I merge scanned documents into one PDF?
Drop the files into a merge tool in the order they should appear, drag them into sequence, and export one PDF. Keep scans and photos separate until you have checked the order: the page numbers you quote later must match the file you send.
Sort before you merge
Merging is irreversible in the sense that matters: once the bundle is numbered and sent, reordering it means renumbering and resending.
Name the files so the order is obvious before they go in — 01-agreement, 02-exhibit-a — rather than relying on the tool to guess. Most scanners name files with a timestamp, which sorts correctly only if every page came from the same machine.
The merge itself
- Drop every file in, including phone photos if that is all you have.
- Drag the entries into the final order. Check the page count as you go.
- Merge. The originals are untouched; you get a new file.
- Number the pages, then sign. Numbering before merging is the mistake that breaks the index.
- Open the result and scroll once. A page that failed to load is visible here and nowhere else.
When the pages do not match
A bundle of A4 scans and phone photos will have different page sizes. That is usually acceptable — PDF readers handle it — but a document that will be printed and bound looks wrong if the page sizes jump.
If a landscape scan appears sideways, rotate it before merging rather than after. Rotating a merged file is possible but you have to find the page again.
Size limits and why they exist
A browser merge holds every page of the batch in memory at once. That is the cost of not having a server, and it is why a batch is capped rather than unlimited in one run.
Larger sets merge in batches: produce two files, then merge those two. The result is identical, and the downloads are unlimited on a pass.
Where this stops
Merging does not compress. Combining five 4 MB scans gives you a 20 MB file. If the recipient has a hard size limit, the fix is smaller scans at the source — 200 to 300 dpi greyscale is usually enough for a signature page.
It also does not repair a broken scan. A skewed page stays skewed unless you crop or rotate it.
Are my scans uploaded to a server?
No. The pages are read and rebuilt in the browser tab. You can confirm it by turning off the network after the files load — the merge and download still work.
Can I merge photos and PDFs together?
Yes. JPG and PNG are accepted alongside PDFs, so a photographed page can sit next to a scanned one in the same bundle.
Will merging reduce quality?
No. Existing PDF pages are copied as they are, not re-rendered, so text stays selectable and images keep their resolution.
Can I remove a page afterwards?
Yes, with Organize PDF. It rebuilds the file from the pages you keep, so the removed page is gone from the new copy rather than hidden.
This page is general information, not advice for your document. The tools do what they say on their own pages, and every limit is printed there.