Document assembly
Merge PDFs by building a packet, not by dropping files into a pile
The Merge tool copies every page from the files you choose into one new PDF, in the order shown in the workspace. It preserves page content far better than converting pages to images, but it cannot tell whether you selected the correct version or duplicated a section.
Decide the packet structure before uploading
For a submission, write the sequence in plain language first: cover letter → form → ID → evidence → appendix. Then add files in that order. Use the arrow controls to correct the sequence before merging.
Version check
Open files with similar names. “final2.pdf” is not evidence that it is newer or correct.
Expected page count
Add the source page counts. The merged result should normally match that total.
Boundary check
Most assembly mistakes appear where one source ends and another begins.
The page count can still look right when the packet is wrong
One missing page plus one duplicate gives you the same total. That is why count is only the first test. Open the last page of each source section and the first page after it.
What merging can change in practice
- Separate document bookmark trees may not behave like one intentionally authored navigation system.
- Existing certificate-based signatures should be treated carefully because the merged output is a new PDF.
- Form fields from multiple sources can create naming conflicts or workflow problems in some documents.
- Different page sizes and orientations remain different unless you standardize them separately.
Merge first, compress last.
If the final packet is too large, compress the completed copy only after order and page count are correct. Repeating conversions before assembly creates more opportunities for quality loss.
A five-point final inspection
- Open the merged download, not just the browser success message.
- Confirm total page count.
- Check every section boundary.
- Look for duplicate first pages and missing backs of scanned documents.
- Verify any links, forms or signatures that matter to the recipient.
File handling
PDF-Lib reads each selected file in your browser and copies the pages into a new PDF there. The source PDFs are not uploaded to PDFNexa. Keep all originals until the combined packet has been accepted.