Merge PDF
Combine two or more PDF files into a single document. Add the files, put them in the order you want and download the result. Everything runs in your browser, so the documents never leave your device.
Drop PDF files here
PDF only. Up to 50 files, 200 MB each.
Your files stay in this browser tab. Nothing is uploaded, saved or logged.
How Merge PDF works
PDFStrong reads each file in a background process of your browser and copies its pages, one file after the other, into a new PDF. Pages are copied as they are, not redrawn: text stays selectable, images keep their original quality, and every page keeps its own size and orientation, so portrait and landscape pages can be mixed freely.
The order of the list is the order of the result. All pages of the first file come first, then all pages of the second, and so on. Use the arrows to move a file up or down, and remove any file you added by mistake, before you merge. The same file can be added more than once if you need its pages twice.
Merging copies pages, not the structure of each source document. Bookmarks, fillable form data and links that jump to another page of the same file belong to the whole source document and may not be carried over. The content of every page is kept.
How to use it
- Select PDF files, or drop them on the area at the top of the tool. You can keep adding files.
- Check the page count and size shown for each file, then use the arrows to set the order.
- Type a name for the merged file if you want one, and choose Merge PDF.
- Download the result. Choose Start over to merge another set of files.
Example
| File, in list order | Position in merged.pdf |
|---|---|
| contract.pdf · 3 pages | Pages 1–3 |
| annex-a.pdf · 2 pages | Pages 4–5 |
| signatures.pdf · 1 page | Page 6 |
Limits and good to know
- Up to 50 files per merge, 200 MB per file and 500 MB in total. Everything is held in your device’s memory while it works, so larger sets can make the browser run out of it.
- Password-protected PDFs and PDFs with editing restrictions cannot be merged. Remove the protection first, which requires the password.
- The merged file is not compressed further. Its size is roughly the sum of the original files.
Frequently asked questions
Are my PDF files uploaded to a server?
No. The files are opened and combined by your own browser, and nothing is sent anywhere. You can check it yourself: open your browser’s developer tools, watch the Network tab while you merge, and you will see no upload. Closing the tab, pressing Start over or removing a file releases the document from memory.
In what order are the files merged?
In the order of the list, from top to bottom. Pages inside each file keep their own order. Use the up and down arrows next to a file to change its position before you merge; the result is not sorted by name unless you arrange the list that way.
Will the merged PDF look the same as the originals?
Yes for page content. The pages are copied, not converted or re-rendered, so fonts, images and layout stay as they were and nothing is recompressed. What is not carried over are document-level features such as bookmarks and form data, because they belong to each source file as a whole.
Can I merge a password-protected PDF?
Not with this tool. A protected file cannot be read without its password, and the merge stops with a message that names the file. Open the document in a viewer that has the password, save an unprotected copy, and add that copy instead. Only do this for documents you are allowed to unlock.
Why is the merged file larger than I expected?
Because nothing is compressed or deduplicated: if two files embed the same font or logo, both copies are kept, so the result is roughly the sum of the inputs. To keep a file small, merge only the files you need and split out the pages you do not.