About this tool
Merging comes up whenever a form wants one document and you have several. A scanned mark sheet, a scanned ID and a covering letter arrive as three separate PDFs, and the upload box accepts exactly one file. This tool copies the pages of each file, in the order you set, into a single new PDF.
Order is the part people get wrong, so it is worth a second look before you run anything. The list on screen is the order of the finished document: the file at the top supplies page 1. The arrows beside each filename move it, and you can remove a file without starting over. If the merged file is out of order, it is almost always because the list was.
Nothing is compressed along the way. Pages are copied with the fonts and images they depend on, which keeps them looking exactly as they did, and means the merged file weighs about as much as the originals added together. If the total is over an upload limit, compress the images before they go into the PDF rather than expecting the merge to shrink them.
All of it runs in your browser. The files are read on your device, joined on your device, and downloaded from your device. That is why there is no queue and no account, and also why a very large batch can feel slow on an older phone: the work is being done by the handset in your hand, not by a server.
How to use this tool
- Add your PDFs. Choose at least two PDF files, or drag them onto the box. Each file can be up to 50 MB and the whole set up to 100 MB.
- Put them in the right order. The merged document follows the list from top to bottom. Use the ↑ and ↓ arrows beside a filename to move it earlier or later, and the × to drop a file you picked by mistake.
- Run the tool. Every page of every file is copied into one new PDF, in list order. When it finishes you will see how many pages the result has.
- Download merged.pdf. The file saves as merged.pdf. Open it and check the page order before you send it anywhere, and rename it if the form you are filling asks for a particular filename.
What this tool does not do
- It cannot open password-protected or encrypted PDFs. Save an unprotected copy first.
- It merges whole files. There is no way to pick pages here — split first, then merge.
- It does not compress anything. Ten 2 MB files give you roughly a 20 MB file.
- Form fields, annotations, bookmarks and unusual page structures may not survive the copy intact.
- There is no page preview. Open the downloaded PDF to confirm the order is right.
Common questions
Do the files get uploaded to a server?
No. The PDFs are read into your browser's memory, joined by your own device, and handed back as a download. There is no upload step, so nothing sits on anyone's server afterwards and the tool keeps working when your connection drops.
How is the order decided?
By the list, not by filename or by the order you selected them in the file picker. Whatever is at the top of the list becomes page 1. The arrows beside each filename move it up or down.
Can I merge only pages 2 to 4 of one file?
Not here. Merge takes every page of every file it is given. Use Split PDF first to pull out the pages you want as their own file, then bring that file into the merge.
It says my PDF could not be opened.
Password-protected and encrypted PDFs are not supported, and a damaged file gives the same message. Open the file in whatever app can already read it, save an unprotected copy, and merge that.
How many PDFs can I merge at once?
There is no fixed count. The real limits are 50 MB per file, 100 MB across the set, and how much memory your phone or laptop has free. On an older Android handset a large batch can take a while, because the joining happens on the device.
Why is the merged file as big as all the originals put together?
Because there is no compression step. The pages are copied as they are, along with the fonts and images they use, so the result is roughly the sum of its parts.