Combine PDF Files Into One Document

Merge multiple PDFs into a single file with these tools

Multiple pdf icons in different colors

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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, such as when a larger document is scanned one page at a time into individual files. Here are several ways to merge multiple PDF files into a single document.

Adobe Acrobat DC

Screenshot of Adobe Acrobat DC

Clayton Kroh 

Adobe's popular Acrobat Reader is free and lets you to view and print PDF files as well as add annotations if you wish. However, to further manipulate these files or to combine multiple PDFs into one, you'll need to 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.

Using Acrobat DC

in Acrobat DC, click Tools > Combine Files. 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 added, you can adjust the order (including individual pages) by dragging-and-dropping each to the desired location.

Click Combine Files to complete the process.


Screenshot of PDF in preview

Clayton Kroh

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.

Using 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, click View.
  3. Make sure Thumbnails is checked in the dropdown menu. If it isn't, click 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 will appear after this selected page).
  5. Click Edit in the Preview menu.
  6. When the dropdown menu appears, select Insert > Page from File.
  7. In the Finder window locate the second PDF file you want to import into the current one and click Open.
  8. Repeat steps 4 - 7 for each additional PDF file you need to import.
  9. Drag-and-drop thumbnail pages to change their order if you need to.
  10. Once you are satisfied with your combined PDF, click File > Save.

PDF Merge

screenshot of PDF Merge site

Clayton Kroh

Several websites offer PDF merging services. Many 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. There is a limit of 10MB for files that are uploaded to be combined.

They also offer an affordable downloadable app that you can use to merge PDFs offline. Only a Windows version is available.

Using PDF Merge

Click Choose File, select a PDF file you want to merge and click Open. Do this for each PDF file you want to merge until you have all your files selected and queued. You can click More files to add another field to add another file.

The files will be combined in the order in which you select and upload them.

Click Merge to combine all selected files. The final combined PDF can then be downloaded to your computer.

Combine PDF

screenshot of Combine PDF

Clayton Kroh

Combine PDF is another web-based tool for merging multiple PDF documents into a single one. You can 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.

Using Combine PDF

Combine PDF lets you drag your PDF files directly onto their web page or upload them in the traditional fashion by clicking Upload Files. Adjust the order of your uploaded files to be combined by dragging them in the queue.

When you're ready, click Combine and the merged PDF file combinepdf.pdf will be downloaded to your computer.

Merge PDF

screenshot of Merge PDF on smallpdf

Clayton Kroh

Merge PDF, part of the 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 as 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 file formats.

Using Merge PDF

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

Where it sets itself apart is through the added ability to upload files from cloud services Google Drive and Dropbox. Click either From Google Drive or From Dropbox to bring up a login window. Enter your login credentials for the cloud service and you'll see your cloud-based files. Select the file you want to upload and click Choose.

Combining PDF Files on Mobile Devices

Screenshot of PDF Converter app

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There are also Android and iOS apps available that can help you 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. Those options listed below seem to be the most reliable among a mediocre group.


  • 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 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, you can quickly merge two or more PDF documents without much hassle. The pro version lifts this restriction and removes all ads.

iOS (iPad, iPhone, iPod touch)

  • PDF Converter: Allows you to combine PDF files on your Apple iPhone or iPad 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 that is free up to a certain amount, beyond which a fee will be incurred.
  • 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.