Merging does not rebuild anything. Pages are laid end to end with their text, fonts and images intact, so the result is almost always faithful to the originals. There are only two things to watch: the order of the files, and a few things that quietly disappear.
Merge PDF
Drop PDF files here
PDF · up to 100 MB per file · up to 20 files
Files are deleted after 2 hours. You can delete them right after downloading.
Order is where it goes wrong
Files are merged in list order, not in name order.
Files are merged in the order you add them, not in the order of their names. Drop a whole folder in at once and the order may not be what you expect, especially with names numbered 1, 2, 10. Many systems sort names character by character, so 10 lands right after 1 and before 2.
The reliable way:
Steps
Rename the files with numbers of equal length
`01`, `02`, … `10`.
Add the files to the tool one by one, in the order you want.
Read through the list once before you merge.
Open the result and check the first page of each part.
What merging loses
Digital signatures and internal links are the two things most likely to break.
These three go away without a warning, so check if your document depends on them:
- Digital signatures are invalidated, because the file is no longer the one that was signed.
- Form fields with the same name become one. If two files both have a field called
fullname, filling one fills the other after merging. - Internal links can point somewhere else. Bookmarks usually survive, but links to a page within the old file may end up on the wrong page.
Merging documents that need a digital signature? Merge first, then sign. If the original signatures must stay valid, send the signed files separately instead of merging them.
After merging
A document assembled from several sources usually wants continuous page numbers. If it has grown large, compress the PDF before sending. And if you only need a few pages from each file, split those out first, then merge.
Related tools · PDF tools
Frequently asked questions
How many files can I merge at once?
The limit is total size, not file count. If you hit it, merge in groups and then merge the groups.
Does merging reduce quality?
No. Pages are copied across as they are.
I only need a few pages from each file.
Split each file first with Split PDF, then merge the parts you kept.
Are my files kept on the server?
They are deleted after 2 hours, and you can delete them yourself as soon as you have the result.
Try it on your own file
Free, no sign-up. Files are deleted after 2 hours.
