How to Combine PDF Files into One Document

Multiple PDFs driving you nuts? Just merge them into a single file

Combining PDF files
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The PDF file format is widely used for a number of purposes including contracts, product manuals and much more. Scanned documents are often saved as PDFs as well, either by default or after a conversion process.

You may have the need to combine several PDFs into a single file, which is often the case when a larger document is scanned one page at a time. There are several ways to merge multiple PDF files into a single document, and we detail some of the best below.

Adobe Acrobat DC

Adobe Acrobat DC

The free version of Adobe's popular Acrobat Reader allows you to view and print PDF files as well as add annotations if you wish. To further manipulate these files or to combine multiple PDFs into one, however, you'll need to install Acrobat DC.

Available for a monthly or yearly subscription fee which varies based on application version and length of commitment, Acrobat DC makes it very easy to merge PDF files. If you only have a short-term need, Adobe offers a 7-day free trial of the software which contains no limitations in terms of functionality.

Once you're up and running, select Combine Files from Acrobat's Tools menu. When the combine files interface is displayed you'll be given the option to add as many files as you wish. After all files have been incorporated, you can order them accordingly (including individual pages) by dragging and dropping to the desired location. Click on Combine Files to complete the process.

Compatible with:

Preview

Screenshot of PDF in preview

Mac users can utilize the built-in Preview application to combine PDF files, eliminating the need for any third-party software or online service altogether. Take the following steps to merge PDFs via the Preview app.

  1. Open one of the PDF files in the Preview app.
  2. Click on View in the Preview menu, located at the top of the screen.
  3. When the drop-down menu appears, look to see if there is a check mark next to the Thumbnails option. If there isn't, click on it once to enable thumbnail preview.
  4. In the thumbnail preview pane, located on the left-hand side of the app window, click on the page within the PDF where you wish to insert another PDF file. This step is only applicable if the current file is more than one page.
  5. Click on Edit in the Preview menu.
  6. When the drop-down menu appears, hover your mouse cursor over the Insert option. Select Page from File.
  7. A pop-out Finder window will now appear, asking you to select a file. Locate and choose the second PDF that you wish to merge and click on the Open button. You will now see that both files are combined into one. You can continue to repeat this process as many times as necessary, as well as delete or reorder individual pages within the thumbnail preview pane.
  8. Once you are satisfied with your combined PDF, click on the File menu at the top of the screen and choose Save.

Compatible with:

  • macOS

PDF Merge

PDF Merge

Several websites offer PDF merging services as well, many which are ad-driven and therefore free of charge. One of these is PDF Merge, where users can upload multiple files from right within their web browser. Clicking on the Merge button combines all files in the order that they were uploaded, and instantly downloads a single PDF to your hard drive.

The only notable limitation is a 15MB size limit. A desktop version of PDF Merge is also offered for Windows users who prefer to work offline.

Compatible with:

Combine PDF

Combine PDF

Another web-based tool, Combine PDF allows you to drag files directly onto their web page or upload them in the traditional fashion. You can then merge up to 20 files and/or images into a single PDF file with the click of a button at no cost, placing them in the desired order beforehand.

Combine PDF claims to delete all files from their servers within one hour of upload. One potential negative is that the website does not utilize the HTTPS protocol, making it less secure than some of the others on our list.

Compatible with:

Merge PDF

Merge PDF

Merge PDF, part of the Smallpdf.com site, is a free-to-use browser-based solution that lets you incorporate files not only from your local device but also from Dropbox and Google Drive. You're given the ability to drag-and-drop pages at will, reordering and deleting them if you like prior to combining into one PDF file.

All transmissions are deemed secure and files are permanently deleted from the Smallpdf servers within an hour. The site also offers many other PDF-related services including viewing and editing tools as well as the ability to convert to or from other file formats.

Compatible with:

Combining PDF Files on Mobile Devices

PDF Converter app
Screenshot from iOS.

Up to this point we've covered several browser and application-based options that merge PDF files on desktop and laptop computers. There are also a limited number of Android and iOS apps available that can help you combine these files on a smartphone or tablet.

Many mobile apps that promise this functionality either do not deliver the expected features or are poorly developed, resulting in frequent crashes and other unreliable behavior. Those options listed below seem to be the most reliable among a mediocre group.

Android

  • PDF Utils: This oft-updated app allows you to combine a large number of PDF files from your Android device, as well as access many other useful features. Basic functionality is available without a fee, while an ad-free experience can be achieved through in-app purchases.
  • PDF Utility: Despite some limitations in the free edition of this app including a maximum file size of 2.5MB, you can quickly merge two or more PDF documents without much hassle. The Pro version lifts this restriction and removes all ads for $2.49.

iOS (iPad, iPhone, iPod touch)

  • PDF Converter: Allows you to combine PDF files on your Apple phone or tablet fairly easily, with in-app purchases required to remove some size and file number limitations.
  • CloudConvert: This app was not designed specifically for PDF files, but does offer merge functionality which is free up to a certain amount at which point a fee will be incurred.
  • PDF Expert: One of the more well-known and stable apps on the list, PDF Expert's $9.99 price tag is well worth it if you find yourself combining PDF files from your iCloud library on a regular basis.