Merge PDF Files
Put several PDFs into one file, in the order you want.
Combine PDF Files Into One
Scans that came out as separate files, an invoice and its receipts, the chapters of a report: merging them gives one document that is easier to send and to archive. This page opens the PDF Tools on the Merge tab.
Mixed page sizes
Each page keeps its own size and orientation, so an A4 letter, a US Letter form and a landscape table can be merged without any page being stretched or cropped. If a scanned page is sideways, turn it in Organize pages before you download.
Order and file names
Files are added in the order you choose them, which is usually alphabetical. Numbering the files before you add them, such as 01-cover.pdf and 02-contract.pdf, saves reordering them afterwards.
Related tools
To cut a long PDF into parts, use split PDF. To add photos to the document, turn them into a PDF with image to PDF first and merge the result.