How to merge PDF files
Updated
Contents
To merge PDF files, open the Merge PDF tool, add two or more PDFs, and drag them into the order you want. The tool combines them into a single PDF that you save straight to your device.
What makes this approach different is where the work happens. Merge PDF runs entirely in your browser, so your files stay on your device from start to finish — there is no server step in the middle. There is also no account: open the page, add your files, and merge.
The combined PDF follows your list from top to bottom, so a stack of scans, chapters, or exhibits comes out exactly as you arranged it. If you later need the reverse operation, Split PDF breaks one document into separate files by page range, fixed intervals, or one file per page, and Organize Pages rearranges pages inside a single document.
Step by step
- 1Open the Merge PDF tool.
- 2Add two or more PDF files — they stay on your device the entire time.
- 3Drag files into the order you want; the combined PDF follows your list from top to bottom.
- 4Use each row's move buttons to shift a file up or down instead of dragging.
- 5Double-check the order — the file at the top of the list becomes the opening pages of the result.
- 6Merge, then save the combined PDF to your device.
Get the order right before you merge
The merged document is built from your list, top to bottom: the first file in the list becomes the first pages of the output, and every file after it is appended in sequence. Drag files into position to set that order, or use the move buttons on each row if you prefer clicking to dragging.
It is worth a final glance at the list before you merge. Reordering happens before the merge runs, so arranging the list correctly the first time saves you a second pass. If you want finer control after the fact, Organize Pages lets you reorder, rotate, duplicate, and delete pages on a visual page board.
Start the merged PDF with a contents page
Tick “Add a contents page” before you merge and the combined PDF opens with a page headed Contents: one line per file, its name and the page it starts on, and clicking a line jumps to that page. The numbers count the contents page itself, so they match the page numbers your PDF reader shows.
The contents follow your list from top to bottom and the pages you picked for each file, so a file you took only three pages of starts where those three pages are. A long list continues onto a second contents page. Bookmarks, including the ones “Add a bookmark for each file” writes, still open the right pages.
Where the merge actually runs
Merge PDF is an in-browser tool. The processing runs on your own device, and your files stay there from start to finish — they are never sent to a server as part of the merge. That also means there is no account: the browser you already have does the work.
One honest nuance: the tool is not fully offline. The page and its processing engine load over the network, and parts of the engine are fetched the first time a step needs them. The processing itself runs on your device. Rendering a page that holds a JPEG 2000 or JBIG2 image, as scanned documents often do, downloads an image decoder from our site the first time it is needed, and that step needs a connection. Chinese, Japanese or Korean text whose font is not embedded in the PDF needs a character map, downloaded from our site the first time it is needed, and that step needs a connection. Drawing text in a script outside the Western European alphabet downloads a matching font from our site the first time it is needed, and that step needs a connection.
Inputs, output, and limits
Merge PDF accepts PDF files and produces a single PDF. Each file you add can be up to 100 MB, and you need at least two files for a merge to make sense — the tool is built around combining several documents into one.
If the combined document ends up heavier than you would like, Compress PDF can follow up: its lossless structural repack always runs in your browser, with deep image compression available as an optional, clearly labeled secure-server step.
Common questions
Do my files get sent to a server when I merge PDFs?
No. Merge PDF runs entirely in your browser, and your files stay on your device from start to finish.
How large can each PDF file be?
Each PDF you add can be up to 100 MB.
Can I merge PDF files without an account?
Yes. No account is required — open the tool, add two or more PDFs, set the order, and merge.
Does merging PDFs work offline?
Not fully. The page and its processing engine load over the network, and parts of the engine are fetched the first time a step needs them. The processing itself runs on your device. Rendering a page that holds a JPEG 2000 or JBIG2 image, as scanned documents often do, downloads an image decoder from our site the first time it is needed, and that step needs a connection. Chinese, Japanese or Korean text whose font is not embedded in the PDF needs a character map, downloaded from our site the first time it is needed, and that step needs a connection. Drawing text in a script outside the Western European alphabet downloads a matching font from our site the first time it is needed, and that step needs a connection.
How do I control the page order in the combined PDF?
The output follows your file list from top to bottom. Drag files into position before merging, or use each row's move buttons. To rearrange pages inside the result afterward, Organize Pages handles reordering, rotating, duplicating, and deleting pages on a visual page board.