Merge PDF files into one document

Merge writes between two and fifty PDFs into a single document, in the order you put them in. Nothing is re-rendered: every page arrives with the text, images and page size it already had. Bookmarks are kept, the files’ form fields are joined rather than overwritten, and by default each file leaves a bookmark at the page where it begins.

Nothing is re-rendered, so mixed page sizes stay mixed: an A4 report followed by a US Letter appendix comes back as exactly that. Resize afterwards if it all has to be one size.

Merge PDFs now

No account. Your upload is deleted after 2 hours, the result after 24 hours.

How it works

  1. Add the files in reading order. Two to fifty PDFs. The order in the list is the order in the result, so arrange them before you run it — file pickers sort by name, and 10 sorts before 2 unless you have numbered them 01, 02, 03.
  2. Decide what happens to the bookmarks. Leave both bookmark options on and you get an outline with one entry per file above whatever outlines the sources brought with them. Turn them off for a plain document with no navigation panel.
  3. Run it and check the joins. One PDF comes back, named after your first file. Open it at the pages where each source begins: a wrong order shows itself there and nowhere else.

What the options do

The form above lists the options this tool is running today, straight from the server. This is what they are for.

Pages to take from each file
The range applies to every file, not to one of them: 1-3 takes the first three pages of each. It is meant for the case where all the files have the same shape — twenty scanned forms whose second page is a blank back, say. Setting a range also rebuilds each file before merging, which leaves the sources’ bookmarks and form fields behind, so leave it at ‘all’ if you need those. For different ranges per file, extract from each one first and merge the extracts.
Add a bookmark for each file
Puts one top-level bookmark per file at the page where that file starts, named after the file with its extension removed. With twenty exhibits this is the difference between a document you can navigate and 300 undifferentiated pages. Rename the files before you upload if you want the outline to read well.
Keep the original bookmarks
The outlines the sources brought with them. On, they are kept and sit under the per-file bookmarks. Off, the merged document starts with no outline at all — which is what you want when the sources came out of a system that bookmarks every paragraph.

What this tool does not do

  • Nothing is re-rendered, so mixed page sizes stay mixed: an A4 report followed by a US Letter appendix comes back as exactly that. Resize afterwards if it all has to be one size.
  • It cannot open a password-protected file. Unlock it first — that needs the password you already have — and then merge.
  • A digital signature on any of the source files will not survive. Signing covers the bytes of the file it was applied to, and this is a new file.
  • Fifty files per run. For more, merge in batches and then merge the batches; a merged file is an ordinary PDF.
  • It does not remove duplicate pages, sort by name or notice that you have uploaded the same file twice. The list is the order you get.

What happens to your file

The file is uploaded because Merge PDF runs on our server rather than in the browser tab. It is kept for at most 2 hours and the result you download for 24 hours, then a scheduled job deletes both — a job has to be able to read the file while it runs, and you have to be able to retry a failed conversion without re-uploading. Neither needs longer.

Nothing about the contents is logged, and no one reads your documents. The retention page lists the same numbers the code enforces, and the privacy policy says who can reach the storage they sit in.

Questions

Does merging keep form fields working?
Yes, as long as you leave the page range at ‘all’. Fields are joined rather than overwritten, so two copies of the same form do not end up sharing one value — which is what happens when a merger only copies the pages.
Can I take only some pages from each file?
Yes, but the range applies to every file: 1-3 takes the first three pages of each. Taking a range also drops the sources’ bookmarks and form fields, so for anything more selective, extract the pages you want from each file first and merge those.
What order will the pages come out in?
The order the files sit in the list, top to bottom, and within each file its own page order. If you are uploading a folder of scans, name them 01, 02, 03 rather than 1, 2, 3, or your file picker will hand them over with 10 before 2.
How many PDFs can I merge at once?
Fifty. If you have more than that, merge them in batches of fifty and then merge the batches — a merged file is an ordinary PDF and can go through again. The result is the same either way.
Will the merged file be smaller than the originals added together?
Barely. Each file brings its own images and embedded fonts and nothing is shared between them, so the only saving is the file structure you stop repeating. Run the result through compress if it has to fit an email.
Can I merge a password-protected PDF?
Not directly. The tool refuses a file it cannot open and says so rather than producing something incomplete. Unlock the file first, then merge; unlocking needs the password, because this is not password cracking.