Merge PDFs, in the order you put them
Add the files, drag them into the order you want, and get one document. No signup, no watermark, no page limit, and nothing is uploaded — the pages are copied inside this tab. Each file's original page size is kept, so an A4 invoice and a Letter-sized receipt stay the shape they were.
Drop PDFs here, or click to choose
Several at once is fine. They merge in the order shown below.
What merging actually involves
A PDF is a directed graph of numbered objects. Pages are leaves of a page tree, and each page points at its content, fonts, images and so on by object number. Merging two PDFs means walking the second document's page tree, copying every object a page depends on into the new file under a fresh object number, rebasing all the internal references, then rebuilding the cross-reference table so a reader can find everything.
That is why this page ships a real library instead of a clever trick. The image case can be done with arithmetic, because a JPEG can be carried inside a PDF verbatim. Page trees cannot: get one reference wrong and the file opens with blank pages, or opens in one reader and not another.
What survives a merge, and what does not
| Thing | After merging |
|---|---|
| Pages, page order, page size | Kept exactly |
| Text, images, vector art | Kept, still selectable and searchable |
| Embedded fonts | Kept |
| Links inside the document | Kept |
| Bookmarks and outlines | Not carried over. The sidebar tree is lost |
| Form fields | Flattened or lost, depending on the source |
| Comments and annotations | Usually lost |
| Document metadata (title, author) | Reset to a generic title |
| Digital signatures | Invalidated. Editing a signed PDF always breaks the signature |
The first four rows are what most people actually need. The rest is the reason a signed contract or a bookmarked manual should not be merged with this, or with anything else.
Password-protected files
A PDF with an open password is encrypted, and its pages cannot be read without the key. This tool cannot unlock it, so it reports the file by name and leaves it out of the merge rather than quietly producing a document with pages missing. Unlock it in a reader you already own, save a copy, then merge that.
Ordering
The list order is the page order, and it starts as the order you added the files. Move a file with Up and Down; the number badge on the left shows how many pages it contributes, so you can see the total before merging. Files that failed to read are shown in red and are ignored by the merge.
Why not upload it somewhere
The PDFs people merge are usually not the fun kind: contracts, bank statements, medical letters, invoices with an address on them. Uploading those to a free converter means a copy on a stranger's disk, and the free ones are free because the files have a second use.
Everything here happens in the tab. There is no upload request, nothing is queued, and no copy exists anywhere but your own machine. You can prove it: open the developer tools, watch the Network tab while you merge, and see that nothing is sent. Then disconnect from the network and merge again — it still works.
Questions
Is there a limit on file count or size?
No fixed limit; memory is the real one. A few hundred pages is comfortable on a desktop browser. If it stalls, merge in two passes — merge the first half, then merge that result with the second half.
Does it work with scanned PDFs?
Yes. A scanned page is an image on a page, and images copy across like anything else. The result is not searchable, but it was not searchable before either.
Can I merge a PDF with photos?
Yes if the photos are already a PDF. To turn photos into one first, use Images to PDF, which can also do it without re-compressing them.
Why did my bookmarks disappear?
Because the outline tree is a separate structure that points at page objects, and it has to be rebuilt, not just copied. Most free mergers drop it too; the ones that keep it are usually the paid desktop applications.
Can I split a PDF with this?
Not yet. Splitting is its own job — choosing page ranges and writing several outputs — and it is on the list.