Merge PDF Files
Combining PDFs is the job people reach for when a report arrives in three parts, when a scanned signature page has to join the contract it belongs to, or when an application wants one file and you have six. Drop them here, drag them into the order you want, and download one document. Nothing is uploaded: the files are read by this page, rearranged by this page, and saved by this page.
Drop the PDFs you want to combine
Up to 30 files. They are combined in the order you arrange them here, and every byte stays in this browser tab.
Build the document instead of assembling it
If you are merging the same cover page onto every report, that is a template. Moda makes the document once and exports the PDF.
Try Moda free →Order is the whole job, so it is the whole interface
Most merge tools sort by filename and let you fix it afterwards, which is how “Appendix” ends up before “Chapter 1” and “part10” before “part2”. Here the list you see is literally the order of the output — the first row is page one. Move a document with the arrows on its row, remove one without starting over, and add more at any point. The page count next to each file is read from the file itself, so you know how long the finished document will be before you make it, not after.
What survives the merge, and why that matters
This tool copies pages, it does not re-render them. Every page arrives in the new document with its original content stream intact, which means the text stays selectable and searchable, embedded fonts come along, internal and external links keep working, and a vector chart stays a vector chart rather than becoming a picture of one. That is worth knowing because the cheapest way to build a merge tool is to rasterize every page — the output looks identical on screen and is useless the moment anyone tries to copy a paragraph out of it or the file has to be printed at a size other than the one it was rendered at. The one thing that does not survive is document-level structure that cannot belong to two documents at once: bookmarks, the table-of-contents outline, and form-field values are dropped rather than merged into something wrong.
Limits, stated plainly
Thirty files at a time, 100 MB per file, 300 MB across the queue, 500 pages in any one document and 1,000 pages in the merged result. Those numbers are not arbitrary caution: everything happens in your browser tab, which has a memory budget measured in low hundreds of megabytes, and a tool that accepts a 2,000-page merge and then freezes is worse than one that says no. If a file crosses a limit you get a message naming which limit and which file, and the rest of the queue still works — a merge of five documents is not abandoned because the sixth was too big.
Password-protected and damaged files
A PDF with an open password is refused by name rather than half-read. Removing PDF passwords is deliberately not something these tools do, and a merge tool that silently produced a garbled document from an encrypted input would be worse than one that declines. Open it in any PDF reader with the password, save an unprotected copy, and merge that. Files that are truncated, still downloading, or actually a Word document with a .pdf name fail the same way: named, individually, without taking the rest of the queue down.
Frequently asked questions
Are my PDFs uploaded anywhere?
No. The merge happens with JavaScript running inside this page — the files are read from your disk into the tab, the pages are copied into a new document in memory, and the result is handed to your browser as a download. There is no request to a server carrying your document at any point, which is the part that matters when the thing you are merging is a contract, a medical record, or a tax return.
Is there a watermark or a page limit on the free version?
There is no watermark and no paid version. The caps that exist — thirty files, 1,000 pages out — are the limits of doing this in a browser tab, not a sales tactic.
Will the merged file be as small as the originals added together?
Usually slightly smaller. Pages are copied with their resources, and where two source documents embedded the same font the copy is made once rather than twice. It will not be dramatically smaller — merging is not compression. If the result is bigger than you want, the compress tool is the next step.
Can I merge only some pages from each file?
Not on this page — this one takes whole documents. Pull the pages you want out of each file first with the split tool, then merge the results. Keeping the two jobs on separate pages is deliberate: a single screen that did both would need a page selector per file, and the common case is combining whole documents.
Do bookmarks and form fields survive?
Page content does; document-level structure does not. Bookmarks and the outline tree are dropped, and form fields come across as their visual appearance rather than as fillable fields. Both are cases where merging two documents’ structures would produce something plausible and wrong — two conflicting outlines, or two fields with the same name — so the tool drops them rather than guessing.