How to combine PDFs into one file
Combining PDFs comes up all the time: a contract and its addenda, three scanned pages that should be one file, an application and its attachments. Every computer can do it, though Windows needs a little help. Here are the built-in ways, plus a shortcut when the reason you're combining is to get everything signed.
Updated November 5, 2026 · 3 min read
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On a Mac, with Preview
Preview saves changes as you go, so make a copy first: open each PDF and choose File › Duplicate, then work in the copies.
- 1
Open the first PDF and show thumbnails
Open the PDF that should come first in Preview and choose View › Thumbnails. The pages appear in the sidebar.
- 2
Drag the other file in
To add a whole PDF, drag its icon from the Finder onto the sidebar, dropping it between pages or after the last one.
- 3
Or take just some pages
Open the second PDF, show its thumbnails too, and drag the pages you want into the first file's sidebar. Hold Command and click to pick pages that aren't next to each other.
- 4
Put them in order and save
Drag thumbnails up or down to reorder them, then choose File › Save, or File › Export as PDF to save it under a new name.
On Windows
Windows doesn't include a tool that merges PDFs. Microsoft Print to PDF and the Edge browser can save a PDF, but only one file at a time. The usual options are Adobe Acrobat, if your company already pays for it, or a free online merge tool, such as Adobe's own Merge PDFs page, which runs in the browser: upload the files, drag them into order and download the combined PDF.
Think before you upload
An online merge tool sends your files to someone else's server. That's fine for a menu or a flyer. For a contract with someone's address, pay or ID number, use a tool you already trust with that information.
On an iPhone or iPad
The Files app can turn several selected files into one PDF. Open the folder, tap Select, choose the files in the order you want, then look for Create PDF behind the More button. Apple has moved this option between iOS versions, so if you don't see it, update iOS or use the Mac or online route. The SignMaster app for iPhone and iPad also has a PDF editor that merges PDFs.
Combining PDFs to get them signed
If the files are going out for a signature, you don't need to merge them first. In SignMaster, one send is an envelope, and an envelope can carry several files:
- Add every file on the Document step with Browse files, or drag them in together. JPG and PNG photos are accepted too and become PDF pages.
- Set the order by dragging the files. That's the order the signer reads them in.
- Place fields on each file, using the file switcher in the Fields step.
- Get one PDF back. When the last person signs, every file is merged in your order into a single signed PDF, followed by the certificate of completion.
Need a page from another file inside one of the documents? Open the page's menu in the Fields step and choose Insert pages before or Insert pages after, then pick the PDF or photo to add.
Questions? Answers.
How do I combine PDFs for free?
On a Mac, Preview does it for free: drag one PDF into another's thumbnail sidebar. On Windows, use a free online merge tool, keeping private documents off sites you don't trust.
Does combining PDFs reduce quality?
Not with Preview or a proper merge tool; they copy the pages as they are. Quality drops only if a tool re-scans or compresses the pages, which some online tools do to shrink the file.
Can I combine a Word document and a PDF?
Save the Word file as a PDF first, then merge the two PDFs. If you're sending them for signature, add both PDFs to one SignMaster envelope instead of merging.
Will the signed copy be one file or several?
One. SignMaster merges the envelope's files, in the order you set, into a single signed PDF with the certificate of completion at the end.
Sources
- Apple, Combine PDFs in Preview on Mac · support.apple.com