Control the document order
Add at least two PDFs, then use the up and down controls to arrange the files. The merger appends each document’s pages in that order to produce one PDF. Remove a mistaken file before starting the merge.
For example, combining a two-page cover and a five-page report should produce seven pages with the cover first. Open the result and check the page count and order rather than assuming the filenames sorted correctly.
Limitations and document safety
The work happens in your browser without uploading the PDFs. Very large or numerous files can exceed available memory. An encrypted or invalid file may be rejected.
Keep original documents, particularly if they include digital signatures or interactive features. Rewriting a PDF can affect those features, so inspect the merged output before relying on it.