How to Combine PDF Files Into One Document

How to magically make six PDFs turn into one document

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, either by default or after a conversion process.

There are times when several PDFs need to be combined into a single file, such as when a long document is scanned one page at a time into six individual files. Here are several ways to make those six PDFs turn into one document.

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Adobe Acrobat DC

Adobe Acrobat DC

Adobe's popular Acrobat Reader is free. Use Acrobat Reader to view and print PDF files, as well as add annotations. However, to further manipulate these files or to combine multiple PDFs into one, install Acrobat DC.

Available for a monthly or yearly subscription fee that 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.

How to Use Acrobat DC
Follow these steps to merge PDF files with Adobe Acrobat DC:

  1. In Acrobat DC, select Tools > Combine Files.
  2. Add as many files as you wish.
  3. Adjust the order (including individual pages) by dragging and dropping each to the desired location.
  4. Select Combine Files to complete the process.
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Screenshot of PDF in preview

Mac users can utilize the built-in Preview application to combine PDF files, eliminating the need (and cost, as Preview comes with macOS) for any third-party software or online service.

How to Use the Preview App on Mac
Follow these steps to merge PDF files with the Preview app:

  1. Open one of the PDF files in the Preview app.
  2. In the menu at the top, select View.
  3. Make sure Thumbnails is checked in the dropdown menu. If it isn't, select it to enable thumbnail preview.
  4. If your open PDF has more than a single page, select a thumbnail in the left-hand side where you want to insert another PDF file. The inserted PDF pages appear after this selected page.
  5. In the Preview menu, select Edit.
  6. In the dropdown menu, select Insert > Page from File.
  7. In the Finder window, locate the second PDF file you want to import into the current one and select Open.
  8. Repeat steps 4-7 for each additional PDF file you want to import.
  9. Drag thumbnail pages to change their order.
  10. Once you are satisfied with your combined PDF, select File > Save.
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PDF Merge

PDF Merge

Several websites offer PDF merging services. Many are ad-driven and free of charge. One of these is PDF Merge. PDF Merge makes it possible to upload multiple files using a web browser. There is a limit of 10MB for files that are uploaded.

PDF Merge also offers an affordable downloadable app that merges PDFs offline. Only a Windows version is available.

How to Use PDF Merge
Follow these steps to merge PDF files with PDF Merge:

  1. Select Choose File, select a PDF file you want to merge, then select Open.
  2. Select More files to add another file. Do this for each PDF file you want to merge.
  3. The files will be combined in the order in which you select and upload them.
  4. Select Merge to combine all selected files.
  5. Download the final combined PDF to your computer.
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Combine PDF

Combine PDF

Combine PDF is a web-based tool that merges multiple PDF documents into a single PDF file. Merge up to 20 files, including images, into a single PDF file for free. Combine PDF claims to delete all files from their servers within one hour of upload.

How to Use Combine PDF
Follow these steps to merge PDF files with Combine PDF:

  1. Drag your PDF files directly onto the PDF Merge web page or upload the files in the traditional fashion by selecting Upload Files.
  2. Adjust the order of your uploaded files by dragging them in the queue.
  3. Select Combine.
  4. The merged PDF file, combinepdf.pdf, will download to your computer.
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Merge PDF

Merge PDF

Merge PDF, part of the site, is a free-to-use browser-based solution that incorporates files not only from your local device but also from Dropbox and Google Drive. Before you combine the files into one PDF file, use Merge PDF to drag-and-drop pages to reorder or to delete them as you like.

All uploads and downloads 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 file formats.

How to Use Merge PDF
Merge PDF is similar to other web-based PDF tools in that you drag-and-drop your files onto the site to upload them, or select files and upload them in the traditional manner.

Where Merge PDF sets itself apart is through the added ability to upload files from cloud services Google Drive and Dropbox.

Follow these steps to merge PDF files with Merge PDF:

  1. Select either From Google Drive or From Dropbox to bring up a login window.
  2. Enter your login credentials for the cloud service and you'll see your cloud-based files.
  3. Select the file you want to upload and select Choose.
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Combining PDF Files on Mobile Devices

PDF Converter app

There are also Android and iOS apps available that combine PDF 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. These options are the most reliable.

  • PDF Utils: This often-updated app combines a large number of PDF files from your Android device, as well as many other useful features. Basic functionality is available without a fee, while an ad-free experience can be had with in-app purchases.
  • PDF Utility: Despite some limitations in the free edition of this app, including a maximum file size of 2.5MB, PDF Utility quickly merges two or more PDF documents without much hassle. The pro version lifts this restriction and removes all ads.
  • PDF Converter: Combines PDF files on your Apple iPhone or iPad fairly easily. In-app purchases remove some size and file number limitations.
  • CloudConvert: This app was not designed specifically for PDF files but does offer merge functionality that is free up to a certain amount, beyond which a fee is required.
  • PDF Expert: One of the better known and stable apps on the list, PDF Expert's price tag is worth it if you find yourself combining PDF files from your iCloud library on a regular basis.