One file beats a folder of attachments
Sending five separate PDFs asks the recipient to download, order, and track them; sending one merged PDF hands them a finished document. That’s why combining is the most common PDF task in real workflows — assembling a job application, stitching scanned contract pages into a single agreement, collating monthly invoices for an expense claim, or bundling a report with its appendices. A single file can’t arrive with pages missing or in the wrong order.
The decision that shapes the result is sequence. Because the merged document is read front-to-back, the order you arrange files and pages in is the reading experience — worth a moment’s thought before exporting.
Assemble deliberately, then check the seams
A reliable routine:
- Add and order — drag files into the intended sequence; the output follows the list exactly.
- Prune pages — drop blank scanner pages or duplicate cover sheets so the merge is clean, not just complete.
- Check the joins — confirm the last page of one document and the first of the next sit in the right order, the spot where mistakes hide.
Mixed page sizes are fine — a Letter page and an A4 page keep their own dimensions in the combined file. Everything runs locally in your browser through the pdf-lib engine, so confidential documents are assembled in memory on your own device and never uploaded, which is exactly what you want when merging contracts, medical records, or financial statements.