How to merge PDFs without breaking order or page sizes

Merging PDFs sounds trivial until the pages come out in the wrong order or a stray blank page ends up in the middle of a submission. A little preparation prevents most problems.

Decide the order first

Many file pickers return files sorted by name rather than the order you tapped them. Rename files with numbers, such as 01-cover, 02-form, 03-receipts, so the order is predictable. PDF Merge joins files in the order the browser provides them.

Clean up before merging

Remove blank pages, duplicates and cover sheets you do not need using Remove PDF Pages. It is easier to fix one small file than to hunt through a 60-page merged one.

Mixed page sizes

Each page keeps its original size, so an A4 file merged with a US Letter file gives a document with two sizes. That displays fine but can scale oddly when printed. If a portal demands a uniform size, convert the source documents consistently before merging.

Bookmarks and forms

The merge copies pages. Bookmarks, links between pages and interactive form fields from the source files may not survive, so fill in and flatten forms first if you need them preserved. Password-protected files must be unlocked before merging.

Check the result

The page count should equal the sum of your files. Scroll through the merged PDF, then check file size; if it is too large to send, see our guide on getting a PDF under the email limit, or use PDF Split to cut it into parts.

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