Merge PDFs in the right order
Published · Updated 2 min read
When you merge several PDFs, the order in which you add the files is the order of the resulting document. A few settings before merging save you from doing it again.
Prepare the order before adding
Add the files in the order you want: the first one added opens the document. A three-page PDF added before a one-page letter gives the three pages then the letter, and the reverse order gives the letter then the three pages. If you made a mistake, the thumbnails let you move the pages, and "Reverse all pages" turns the whole order around before merging.
Different page sizes
Each page keeps its size. An A4 page in portrait, a Letter page in landscape and an A3 page in portrait are found as they are in the merged file: nothing is resized. If uniformity matters, for example for printing, prepare the files beforehand.
The weight of the result
The merged file weighs roughly the sum of the starting files. Three files of 10, 5 and 4 pages, weighing 22.4 MB together, give a PDF of 19 pages and 23.3 MB. Merging does not reduce the weight. If the result is too heavy for sending, the guide Send a PDF that is too heavy by email explains what to do next.
What passes from one file to the other
The text, the links and the page comments are kept. The title, the author and the attachments of the original files are not carried into the result: fill them in again if necessary.
Protected files
A password-protected PDF cannot be merged: the tool answers that the PDF may be invalid or protected. Remove the protection first with Unlock PDF, as explained in Open a protected PDF whose password you know.
For which documents
An application file made of several pieces, a report assembled from separate chapters, an invoice and its supporting documents: a single file is easier to send.
Check the result
- Count the pages: the total must be the sum of the files, here 10 + 5 + 4 = 19.
- Go through the document, spotting where one file ends and the next begins.
- Look at the weight of the file.
- Keep the original files.
Frequently asked questions
- How do you choose the order of the pages?
- Add the files in the order you want: the first one added opens the document. The thumbnails let you move the pages.
- Is the merged file lighter?
- No, it weighs roughly the sum of the starting files.
- Can you merge a protected PDF?
- No, remove the protection first. The guide Open a protected PDF whose password you know explains how.
- What happens to pages of different sizes?
- Each page keeps its size: nothing is resized.