How to Merge PDF Files in the Right Order
Merging PDFs sounds simple, but a few small choices decide whether the result is what you wanted: the order of the files, the size limits and what the merged file keeps. This guide walks through the process with the Merge PDF tool.
When merging PDFs is useful
Merging is handy whenever related pages live in separate files. Common examples are scanned pages saved one by one, an application that asks for a single PDF with several documents, chapters of a report written by different people, or invoices that you want to send as one attachment.
A single file is also easier to share, print and keep organised than a folder of loose pages.
Step by step
- Open the Merge PDF tool and choose your PDF files, or drag them into the upload area. You can add several files at once.
- Look at the list. The files will be merged from top to bottom. Use the Up and Down buttons to change the order, and remove any file you do not need.
- Select Merge PDFs and wait until the process finishes. Larger files take longer.
- Check the page count and file size shown in the result, then download the merged PDF.
Getting the page order right
The tool merges whole files in the order shown in the list, and the pages inside each file keep their own order. So if you want chapter 2 before chapter 1, move that file up before you merge.
If the order you need is different inside a single file, merge first and then use the Reorder PDF Pages tool on the result. If you only want some pages of a file, use Extract PDF Pages first to save just those pages, then merge the extracted file.
Limits to know before you start
- Up to 20 files at a time.
- Up to 50 MB per file and 150 MB in total.
- Password-protected PDFs are not supported. Remove the password first, then add the file again.
- If your browser becomes slow, merge fewer or smaller files at a time and merge the results in a second round.
What may not carry over
Bookmarks and interactive form fields from the original files may not be kept in the merged file. If your documents rely on them, check the merged PDF before you send it and keep the originals.
Check the result before you use it
Open the merged file in a PDF viewer and scroll through it once. Compare the total page count with the page counts of your originals, and make sure the first and last page of each part are where you expect them.
It takes a minute and saves you from sending a document with a missing or misplaced page.
If something goes wrong
- A file is rejected as damaged: try opening it in a PDF viewer. If it does not open there, it cannot be merged.
- The merged file looks different from the originals: check that each original opens correctly on its own.
- The browser slows down: merge fewer or smaller files at a time.
Ready to try it? Open the Merge PDF tool. You can also see all guides.