Merge PDF

Add 2 or more files, then arrange them in order.

Merge PDF joins several PDFs into one file, in the order you set. The order is the part worth slowing down for — a merge is not something you notice went wrong until someone opens page 14 and finds the appendix sitting in the middle of the contract. Arrange the files first, then merge.

The usual reasons are administrative rather than creative: an application that asks for one attachment when you have a CV, a covering letter and three certificates; an expense claim built from a dozen separate receipts; a report where each chapter came back from a different person. In every one of those cases the requirement is a single file, and emailing five is not an option.

Pages keep their original size, which means a merge of A4 documents with a US Letter one produces a file where the page dimensions change partway through. That is correct behaviour rather than a fault — nothing is being cropped or stretched — but it is worth knowing before you print, because the printer will make its own decisions about how to reconcile them.

Scanned pages and digital pages merge together without trouble, but they behave differently afterwards. Text created in a word processor stays selectable and searchable; a scan is an image of text and stays an image, so searching the merged file will not find anything on those pages. If that matters, the scans need OCR before the merge, not after.

File size adds up roughly as you would expect, and it adds up fastest with scans. Ten pages of typed text might total a few hundred kilobytes; ten high-resolution scans can run to twenty megabytes and hit an email attachment limit immediately. If the merged file is too large to send, compressing it afterwards is usually more effective than trying to shrink each part first.