How to Combine PDF Files into One Document

PDF files are the most reliable file type for storing data and saving information. There are many tools available for combining PDF files into one document. Some easy-to-use and recommended tools for combining PDF files are examined below.

1. Adobe Acrobat Online

The Adobe Acrobat Online PDF Merger software is a helpful tool that you can use to create, edit, and convert PDF files. You can also merge and combine PDF files into one PDF with this tool, both online and offline. The online tool is relatively easy to use, as it is free to use for the first try; after that, you can also use the free trial option or download the app for free use.

How to combine PDF files with Adobe Acrobat

To combine PDF files in Adobe Acrobat, here are some steps to follow:

1. Open Adobe Acrobat Online PDF Merger.
2. After opening the website, you will see the merge PDFs or combine files option.
3. You can either click on the selected files or drag and drop the files in the drop location.
4. After that, your PDF files will open. You can also open multiple PDF files.
5. If the PDF file has a number of pages, you can also edit it by reordering pages.
6. After the modification of PDF files, click on Combine or Merge in the top right corner.
7. Download or share the link of the combined PDF.

Figure 1 – Adobe reader online - Combine Files

Figure 2 – Adobe reader online - Download and Share file

2. Combine PDF - A Free Online PDF Combining Tool

This PDF-merging tool is a free and easy-to-use online tool that allows you to merge multiple PDFs or image files into a single PDF without installing any software. This site has a very straightforward interface and is only used to combine and convert PDF files.

How to combine PDF files with the Combine PDF tool

To merge PDF files with the Combine PDF tool, follow these steps:

1. Open Combine PDF Online Tool.
2. There you will see different "Convert" options for PDF files.
3. Select the Combine PDF menu option.
4. You can upload files or drag and drop multiple files.
5. After adding the PDF files, you can reorder the PDF pages.
6. Click on the Combine button to merge PDFs.
7. Combine PDF Online Tool will automatically download the merged PDF.

Figure 3 – Combine PDF - Upload Files

Figure 4 – Combine PDF - COMBINE

3. SmallPDF - An Online PDF Merging Tool

SmallPDF Merge Tool allows you to merge multiple PDF files into one. Also, you can add a lot of other PDFs into the mix and incorporate them into one single PDF document. This PDF merging tool is browser-based, and thus it also works for Mac and Linux.

How to Combine PDF files with SmallPDF

The steps for merging PDFs in SmallPDF are as follows:

1. Open SmallPDF Merge Tool.
2. Choose File or multiple files, or you can drag and drop PDFs files into the drop location.
3. After adding the PDF files, two options will appear: Merge files, or Merge pages.
4. You can select the Merge files option, because it's free.
5. If you want to use the Merge pages option, you can start the free trial for seven days or purchase the subscription.
6. After deciding the option, you can rearrange the PDF's location.
7. Finally, click on Merge PDF!
8. The merged document will be generated and you can Export or Share the new document in the format you prefer.

Figure 5 – Small PDF - Choose Files

Figure 6 – Small PDF - Merge Files Option

Figure 7 – Small PDF - Merge PDF!

Figure 8 – Small PDF - Export or Share

4. iLovePDF - An Online PDF Combining Tool

iLovePDF strives to bring you the tiniest file size potential while maintaining the highest standards. iLovePDF is secure because they delete archived files within two hours.

How to merge PDF documents with iLovePDF

We can combine PDF files with the iLovePDF tool by following these steps:

1. Open iLovePDF Merge PDFs.
2. Then, select or drag the PDF files into the dropping zone.
3. You can select two PDFs or combine multiple PDFs.
4. After selecting the documents, you can change the order by dragging the second PDF file or any number of files you want to move.
5. Click on Merge PDF.
6. The next tab will open, and it will download the new single document.
7. You can also share the link, delete it now, or share it to Google Drive, etc.

Figure 9 – I Love PDF - Select or Drag Files

Figure 10 – I Love PDF - Merge PDF

IronPDF - Merge PDFs using a C# Library

IronPDF is a .NET Library explicitly designed to handle all PDF-related tasks such as creating PDFs, merging more than two PDF files into one, converting Word files to PDF files, and deleting files.

Those out there with experience of how to merge two or more files into a single document using C# programming know that IronPDF is the best tool for their needs.

IronPDF makes it a piece of cake for developers to manipulate PDF pages and fulfill their needs. For those wondering how it can be done, below is a simple example using Visual Studio.

First of all, open Visual Studio and then go to Tools. Next, extend the NuGet Package manager and click on the second option as shown in the image below.

Figure 11

Then, a NuGet solution window will appear. In this window, go to browse, search for IronPDF and install it.

Figure 12

After that, just write this code to merge two PDF files into one file.

// PM> Install-Package IronPdf

using IronPdf;

var html_a = @"<p> [PDF_A] </p>
<p> [PDF_A] 1st Page </p>
<div style = 'page-break-after: always;' ></div>
<p> [PDF_A] 2nd Page</p>";

var html_b = @"<p> [PDF_B] </p>
<p> [PDF_B] 1st Page </p>
<div style = 'page-break-after: always;' ></div>
<p> [PDF_B] 2nd Page</p>";

var Renderer = new IronPdf.ChromePdfRenderer();
var pdfdoc_a = Renderer.RenderHtmlAsPdf(html_a);
var pdfdoc_b = Renderer.RenderHtmlAsPdf(html_b);
var merged = IronPdf.PdfDocument.Merge(pdfdoc_a, pdfdoc_b);

merged.SaveAs("Merged.pdf");

// PM> Install-Package IronPdf

using IronPdf;

var html_a = @"<p> [PDF_A] </p>
<p> [PDF_A] 1st Page </p>
<div style = 'page-break-after: always;' ></div>
<p> [PDF_A] 2nd Page</p>";

var html_b = @"<p> [PDF_B] </p>
<p> [PDF_B] 1st Page </p>
<div style = 'page-break-after: always;' ></div>
<p> [PDF_B] 2nd Page</p>";

var Renderer = new IronPdf.ChromePdfRenderer();
var pdfdoc_a = Renderer.RenderHtmlAsPdf(html_a);
var pdfdoc_b = Renderer.RenderHtmlAsPdf(html_b);
var merged = IronPdf.PdfDocument.Merge(pdfdoc_a, pdfdoc_b);

merged.SaveAs("Merged.pdf");

' PM> Install-Package IronPdf

Imports IronPdf

Private html_a = "<p> [PDF_A] </p>
<p> [PDF_A] 1st Page </p>
<div style = 'page-break-after: always;' ></div>
<p> [PDF_A] 2nd Page</p>"

Private html_b = "<p> [PDF_B] </p>
<p> [PDF_B] 1st Page </p>
<div style = 'page-break-after: always;' ></div>
<p> [PDF_B] 2nd Page</p>"

Private Renderer = New IronPdf.ChromePdfRenderer()
Private pdfdoc_a = Renderer.RenderHtmlAsPdf(html_a)
Private pdfdoc_b = Renderer.RenderHtmlAsPdf(html_b)
Private merged = IronPdf.PdfDocument.Merge(pdfdoc_a, pdfdoc_b)

merged.SaveAs("Merged.pdf")

For more information on this topic, please visit the following Merging PDFs Example on Iron Software's Website.