How to Combine PDF Files

Knowing how to combine multiple PDFs into a single file is easy and can make you more productive. You don’t want to inflict a half-dozen PDF files on the accounting department, for example, when you can deliver one unified document. Or maybe you have four or five sections of a report that you’ve printed to separate PDFs from Word, Excel, and a photo editor. How do you get them all into a single file? These questions are all the more pressing for people working from home and those trying to go paperless because PDFs easily replace physical documents. People need to know how to organize and manage them.

If you use a Mac, you have the only tool you’ll need already built into the macOS operating system. That said, you can find more flexible and full-featured solutions if you buy commercial third-party apps. 

If you use Windows, you need a third-party app—and you’re in luck because you can find free, open-source options that can do the job. 

With any operating system, you can always use an online app that combines and edits uploaded PDFs, but I’m leery about using almost all of them. Some of these sites seem to have no viable business plan, and their PDF-editing services give them the ability to harvest the data in your files, including invisible metadata that can potentially identify you and your system. You may not want to give that metadata to a site you don’t know anything about and that typically conceals the country in which it’s based. Such a site could profit from your data in ways you wouldn’t like.

There’s one important exception among online PDF-merging tools—Adobe’s free PDF-merge service(Opens in a new window). This is because Adobe is the most prominent player in the PDF world (having created the format in 1991) and the company is open and transparent about its privacy policies.

How to Combine PDFs in Windows

Windows 11‘s default Edge web browser lets you view, draw on, and add text to PDFs, and it can even read them aloud to you. But it can’t merge them on its own. To merge or manage PDF files in Windows, you need either a browser extension or a separate third-party productivity app. Free but limited options are available along with fuller-function commercial choices. We fill you in on the best choices in both categories below.

How To Combine PDF Files In Windows

PDFsam

If your PDF-managing needs are minimal, install the free, open-source PDFsam(Opens in a new window). Start with the free Basic version, and if you like it, consider buying a $69 annual subscription to the full-featured Enhanced version, which lets you edit the contents of PDF files and convert them to other formats. But the free version may be all you need.

(Credit: PDFsam)

The free version of PDFsam lacks some capabilities and ease-of-use features like Adobe Reader’s thumbnail views. But it does let you merge two PDF files by dragging them into a window, which adds them to a list. You rearrange the list by dragging individual lines. You can specify a page range from each PDF, but you’ll have to figure out which pages you want by viewing the document in a separate app like Edge or Adobe Reader. Fortunately, you can open PDFs directly from the file list in PDFsam. 

Another feature included in the free version is the ability to add a blank page at the end of a PDF with an odd number of pages, so the next document in the merged PDF will begin on a right-hand page. You can also add a footer to every page of the merged document. The app also lets you merge bookmarks and form fields from the original files. When you’re ready to merge the PDFs, you just click the Run button.

An especially nifty feature lets you combine two PDF documents, alternating between pages from each file. This means that you can create a single PDF from two separate PDFs containing the front and back pages of an original two-sided document. It took me a while to find this feature in the interface, but I finally figured out that it’s the one labeled “Alternate Mix.” Not the most intuitive name for a feature, but it does work. PDFSam is available for macOS and Debian-based versions of Linux, as well as for Windows.

PDF Merger & Splitter

An alternative freeware app available from the Microsoft Store is PDF Merger & Splitter(Opens in a new window), from a company called AnywaySoft. PDF Merger & Splitter is a free Universal Windows Platform app (commonly called a UWP app) that uses the open-source PDFsharp library for creating PDF files.

(Credit: AnywaySoft)

Compared with PDFsam, PDF Merger & Splitter gives you far fewer options and a less friendly interface, but the app outdoes PDFsam in two ways: It lets you preview PDF files in its own interface, and it can make all the PDFs you combine a single page size. PDFsam only lets you force all pages to have the same size as the first page, while PDF Merger & Splitter also lets you force all pages to have the same size as the largest page or the size used by the most pages. I strongly recommend PDFsam, but PDF Merger & Splitter is worth having for this one feature.

PDF-Xchange Editor, ABBYY FineReader, Adobe Acrobat DC

If you want better visual cues when merging PDFs, you need a commercial app that lets you see the combined PDF before you save it to disk and also displays thumbnail images so you can drag them up and down in a sidebar and rearrange the pages. You can use almost any PDF-editing software, such as the moderately priced PDF-Xchange(Opens in a new window) Editor from Tracker Software. Better would be to choose one of our Editor’s Choice apps—ABBYY FineReader or Adobe Acrobat.

All these apps let you combine PDFs in basically the same way. Here’s how you would do it in PDF-XChange Editor:

1. Go to File > New Document

2. Choose the option to Combine Files into a Single PDF

3. Drag the files that you want to combine into a single PDF into the file-list box. You can add a variety of file types, including PDFs, text files, images, Word, Excel, and PowerPoint documents. The app converts all the files into PDF format before combining them.

When combining files, you can specify the page range of each file that you want to import. You can fine-tune the combination by opening multiple files in separate tabs in PDF-XChange Editor and dragging thumbnail images of the page you want from the source tab to the target tab. If thumbnails aren’t visible, press Ctrl-T or use the View > Panes menu.

The process is very similar in both ABBYY Finereader and Adobe Acrobat.

How to Combine PDFs on a Mac

Unlike Windows, macOS has high-powered, built-in PDF tools, including the deceptively modest-looking Preview app. In all recent macOS versions, starting with Catalina in 2019, the Finder also lets you create or combine PDFs from a menu in its Gallery view (the view that displays a large preview of the current file).

How to Combine PDF Files on a Mac

From macOS Finder

To combine two or more PDFs in the macOS Finder:

1. Switch to Gallery view from the Finder toolbar or the top-line View menu. 

2. Hold down the Command key and select the files you want to combine. 

3. Click each file in the order that you want the files to appear in the combined PDF. When you select more than one file, a Create PDF button appears in the inspector panel at the right. 

4. Click Create PDF and the Finder will create a new PDF on your desktop, containing all the PDFs you selected. 

Alternatively, you can select multiple files in the Finder’s List View, then Ctrl-click or two-finger-tap to bring up a context menu. Choose Quick Actions, then Create PDF.

Even better, you don’t have to limit yourself to merging PDF files. You can select multiple images, like PNG, TIFF, and JPEG files, in addition to existing PDFs, and use the same technique to combine them into one PDF as well.

If the combined PDF file that you create from the Finder doesn’t have its pages in the order that you want, that’s easy to fix. Double-click the PDF to open it in the Preview app. If thumbnails aren’t visible in Preview’s sidebar, go to the View menu to switch them on, and then drag the thumbnails up and down the sidebar into the correct order.

(Credit: Apple)

Preview App

The Preview app offers the same PDF-combining powers as the Finder and can be easier to use for complex tasks. To combine two or more PDF files in Preview, start by making a copy of one of the files and working with the duplicate. This step is an essential precaution because Preview saves the file as you work, and if the results aren’t what you want, you’ll need to do some fancy footwork to get back the original file.

Open the duplicate file. Drag additional PDFs into the sidebar and drop them where you want them in the file. You can move them to the start or end, or between any two existing pages. If you get the location wrong, you can drag one or more thumbnails to the correct location, and you can delete any pages that you don’t want.

What if you only want to merge a few pages from a second PDF file? Open that file in another PDF window and drag the thumbnails that you want into your first PDF file. As always in macOS, you can Shift-click to select a continuous range of pages, or Cmd-click on multiple pages to select pages from anywhere in the file. If some pages get imported in the wrong orientation, use Preview’s toolbar to rotate them.

Sometimes Preview acts in seemingly unpredictable ways when saving a file. So when you have the combined pages arranged as you want them, choose File > Export to PDF and save the merged PDF under its own name. You can also choose File > Close and follow the prompts to save the merged file under the name of the file you started with, but it’s safest to use the Export to PDF option.

Like the Finder, Preview lets you merge any file that Preview can display into an existing PDF. That means you can include PNG, TIFF, JPEG, and other standard image formats. But what if you want to create a PDF that contains a Word document or an Excel worksheet? You can’t drag those documents into Preview, but you can print those files to PDFs using Word and Excel’s Print menus. The resulting PDFs can be used for a merge.

PDFsam and Other Third-Party Apps

If Preview doesn’t provide all the features you need, you can use the impressive fine-tuning features offered by the free open-source PDFSam app (mentioned in the section about merging PDFs in Windows). PDFSam works the same way in macOS as it does in Windows.

Alternatively, if you have a commercial third-party app like Adobe Acrobat, you can merge PDFs in the same way that you merge them in Preview. You can also directly drag files in any file format that Acrobat knows how to convert into PDF, including HTML web pages, plain text files, Word documents, and Excel worksheets. Additionally, Acrobat lets you create a completely new PDF from one or more of these same external formats. Simply use the File > Create menu and follow the prompts.

More PDF Tips

For other ways to convert a PDF into a Microsoft Word file, you can check out our guide. If you need assistance making changes to your PDF once the documents have been combined, check out our story on how to edit a PDF.