How to Merge PDF Files

Add the files you want to combine, then drag them into the required order once they finish uploading. The output document follows that sequence exactly, and arranging files before the merge is far quicker than moving pages afterwards.

Run the merge, download the result and inspect each join: the first page of the second document should follow the last page of the first. For formal submissions, confirm the cover, main form and attachments appear in the requested order, since most organisations reject packs that arrive out of sequence.

A merge does not re-render pages as new images. Pages are carried into the new document as they are, so existing text, vector drawings and images retain their original quality. The text layer survives too, which means the merged file stays searchable and its text can still be copied.

Quality only changes if you apply a separate operation afterwards. If the result is too large, compression is the tool for that, and its effect shows up in scans and photographs rather than in text. Pages of different sizes from different sources are normal in a merged file and are not a quality problem, though it is worth noticing before printing.

File names do not always reflect the intended reading order, and many systems sort file 10 before file 2. Naming files 01-cover, 02-form and 03-attachment with two-digit prefixes removes that ambiguity completely.

Adding page numbers after merging makes it easier for a reviewer to refer to a specific attachment. Do it after the merge rather than before: numbering each file separately produces a final document where the sequence restarts several times.

Make sure you have not included both an old and a new version of the same document, which is the most common mistake in long attachment packs. Password-protected files cannot be merged and must be unlocked first.

If some pages do not belong in the pack, deleting them after the merge is usually easier, because you can see every page in one continuous document. When the final file exceeds an upload limit, compress it and then check small text, signatures and stamps before sending.