- PDF merge tools compared by type
- Ten ways to combine PDFs into one file
- A button or a command: four merge jobs
- Browser tools for joining PDFs and images
- Interleaving pages from two scans
- Open-source and command-line merging
- Questions before you merge PDFs
- My advice for merging PDFs
- Frequently asked questions
The best PDF merger depends on whether you need a button or a command. Browser tools join a few files into one PDF, some also interleave pages from two scans, open-source desktop apps merge inside a program you install, and command-line tools merge from a script. Pick the way you want to work, then the tool.
Merging PDFs sounds like one job. Read the tool pages side by side, though, and you'll find four: joining a handful of files in a browser, interleaving pages from two scans, merging inside an installed app, and merging from a script on a server.
This list covers ten PDF merge tools, using only what each maker's own page says, read on 2 Nov 2026 (as of Nov 2026). It's alphabetical and in no particular order. It's about combining PDFs into one file, so you won't find speed, privacy or file-limit claims here.
PDF merge tools compared by type
| Tool | Type | Good for |
|---|---|---|
| CombinePDF | Online PDF combiner | Joining PDF and image files into one PDF |
| docuPub | Online PDF merge tool | Uploads in formats such as doc, xls and ppt |
| LightPDF | Online PDF tools with AI features | Combining PDFs in the order you specify |
| PDF Candy | Online PDF tool suite | Merging beside Chat with PDF, Translate PDF and PDF to Word |
| PDF Joiner | Online PDF joiner | PDFs and images, reordered by drag and drop |
| PDF24 | Online PDF tools with a desktop app | Merging PDFs with images and Word documents |
| PDF2Go | Online PDF editing suite | Merging beside split, rotate, compress and watermark |
| PDFsam | Open-source desktop app to split and merge PDFs | Basic, Enhanced and Visual editions |
| PDFtk Server | Command-line PDF tool | Merging and collating PDFs from scripts |
| Sejda | Online PDF tools with a desktop version | Alternate and mix merging, plus standard merging |
Ten ways to combine PDFs into one file
CombinePDF
Best for: Combining several PDF or image files into a single PDF without installing software, reordering them by dragging file blocks.
docuPub
Best for: Merging multiple files into one PDF when some uploads are doc, xls or ppt files, with a download for merging locally.
LightPDF
Best for: Combining PDF files in the order you specify on Windows, Mac, Android or iOS, from a site that also lists AI file processing.
PDF Candy
Best for: Joining PDF files online in a suite that also lists PDF to Word, Chat with PDF and Translate PDF.
PDF Joiner
Best for: Merging PDF documents and images into a single PDF file, reordering them with drag and drop first.
PDF24
Best for: Mixed batches: it combines multiple PDFs into a single PDF and also works with images, Word documents and other files.
PDF2Go
Best for: Teams who'll merge, then split, rotate, compress or watermark the same documents in one online suite.
PDFsam
Best for: Splitting and merging PDF files in an open-source desktop app, offered as Basic, Enhanced and Visual editions.
PDFtk Server
Best for: Scripted jobs: merging PDF documents or collating PDF page scans from the command line, on your own machine or a server.
Sejda
Best for: Interleaving pages with its Alternate & Mix tool, which mixes pages from two or more documents, alternating between them.
A button or a command: four merge jobs
Here's what a searcher wouldn't guess: 'merge PDF' covers four different jobs, and the right tool depends on whether you need a button or a command. CombinePDF is for 'combining multiple pdf or image files into a single pdf document'. Sejda's tool list includes an Alternate & Mix option that 'mixes pages from 2 or more documents, alternating between them'.
PDFsam calls itself the app to 'split and merge pdf files', and says it's open source. PDFtk Server is a 'command-line tool for working with pdfs' that can 'merge pdf documents or collate pdf page scans'. Four tools, four very different ways of getting one file out of several.
- Join in a browser: upload a few PDFs or images, put them in order, merge.
- Interleave pages: mix pages from two documents, alternating between them.
- Merge in a desktop app: an installed program that also splits and rotates.
- Merge from a script: a command-line tool you call from your own code or a server.
Browser tools for joining PDFs and images
Eight of the ten tools here are online tools you use from a web page. Two of the simplest describe merging PDF documents and images into a single file, and reordering them with drag and drop before you merge. Another says uploaded files 'can be in various formats like doc, xls, ppt and so on', so a spreadsheet or a slide deck can go into the same merged PDF, and it offers a download if you'd rather merge locally.
A few of these sites are full PDF suites, with merging one tool among many. One lists split, rotate, watermark and compress beside merge, one lists PDF to Word, Chat with PDF and Translate PDF, and one says merging also works with images, Word documents and other files. One suite here also notes that the order you set is the order the pages appear in.
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Interleaving pages from two scans
Interleaving is the merge job people don't know to search for. The open-source desktop app on this list puts it plainly: mixing two files 'taking pages alternatively from each' is 'the tool to use if you have a single-sided scanner'. One online suite here has an Alternate & Mix tool for the same job.
The command-line tool lists collating PDF page scans too, so the same job can run from a script instead of a screen. If you scan paperwork every week, that's worth knowing before you start reordering pages by hand.
Open-source and command-line merging
If you'd rather install a program than use a web page, the open-source desktop app comes in three editions, Basic, Enhanced and Visual, and its page describes it as a desktop app to split, merge, extract, rotate and mix PDF files.
The command-line tool is for a different reader altogether. Its makers say it's 'commonly used for client-side scripting or server-side processing of PDFs', and that it runs on Windows, Mac OS X and Linux. If you merge the same kind of files over and over, a script that calls a command line can do the job without anyone opening a browser.
Questions before you merge PDFs
- Am I joining a few files once, or merging the same kind of files every week?
- Are any of my files images, Word documents, spreadsheets or slides rather than PDFs?
- Do I need to interleave pages from two scans?
- Would I rather use a web page, an installed app or a command line?
- Will I need to split, rotate or compress the result as well?
- Do I need to set the order of the files before merging?
Do you make a PDF merge tool? Tool makers can ask to be considered for a featured place on this list.
My advice for merging PDFs
Work out whether you need a button or a command. For a one-off merge of a few files, one of the browser tools is enough. If your pages came off a single-sided scanner, use a tool with an interleave or mix option instead of fixing the order by hand. And if merging is part of a regular process, look at the open-source desktop app or the command-line tool.
Once the file's merged, you may want it smaller: here's where to compress a PDF. If you need to change what's inside it, see my roundup of the best PDF editors, and to switch formats, here are the best PDF converters.
Want your tool on this list? Featured spots and reviews here are paid partnerships. Here's how to partner with me.
Frequently asked questions
Which of these PDF mergers work in a browser?
Eight of the ten are online tools you use from a web page. Two of those also have a desktop option: one lists a desktop version and one a desktop app. The other two are an open-source desktop app and a command-line tool.
Can I merge images and PDFs together?
Yes, several tools here say so. Two describe merging PDF and image files into a single PDF, one says you can combine multiple PDFs and images into one, and one says merging also works with images, Word documents and other files.
How do I merge pages from two scanned documents?
Use an interleave tool. One online suite here has an option that mixes pages from two or more documents, alternating between them, and the open-source desktop app lists a mix tool for people with a single-sided scanner. The command-line tool lists collating PDF page scans.
Can I merge PDFs from the command line?
Yes. One tool on this list is a command-line tool for working with PDFs, which can merge PDF documents or collate page scans. Its page says it's commonly used for client-side scripting or server-side processing.
Is there an open-source PDF merger here?
Yes. One desktop app describes itself as open source and splits and merges PDF files. It comes in three editions: Basic, Enhanced and Visual. Check each edition's page for what it adds.
Can I change the order of files before merging?
Yes. Two tools say you can reorder files with drag and drop before merging, and another says it combines PDF files in the order you specify. One suite notes that the order you set is the order the pages appear in, so check it before you merge.
