How to Combine Multiple PDFs Into a Single File

The simplest way to merge PDFs depends on what you have on hand

You can merge two PDFs into one using built-in tools on Windows or Mac, free online services, or dedicated PDF software. The fastest route usually depends on whether you're at your computer or on your phone, and whether the PDFs are already organized the way you want them.

On Windows 10 and 11, you can use Microsoft Edge to open both PDFs and print them to a single file. On Mac, Preview handles this natively. If you prefer not to install anything, web-based tools like ILovePDF, Smallpdf, or PDF Merge let you upload files and download the combined result in minutes. For regular merging work, dedicated software like Adobe Acrobat Pro or the free open-source tool PDFtk gives you more control over page order and compression.

Key Takeaways

Windows users can merge PDFs through Microsoft Edge by opening each file and printing to PDF, selecting all pages from both documents.
Mac users can open both PDFs in Preview, drag pages from one into the other, and save as a new file.
Online tools like ILovePDF or Smallpdf work on any device but require uploading your files to a third-party server.
Adobe Acrobat Pro and free alternatives like PDFtk offer more precise control over page order, compression, and metadata.

Merging PDFs on Windows using Microsoft Edge

Open the first PDF in Microsoft Edge by dragging it into the browser window or using File > Open. Once it loads, press Ctrl+P to open the print dialog. In the printer dropdown, select "Print to PDF" or "Microsoft Print to PDF." Under "Pages," select "All" to include every page from the first document.

Before you print, open the second PDF in a separate Edge window or tab. After printing the first PDF to a temporary location (like your Desktop), open the print dialog again, but this time you'll need to use a different approach: print the second PDF to the same file, choosing "Append to file" if the option appears. If your version of Edge doesn't show that option, you'll need to use a dedicated tool instead to combine the two printed PDFs.

This method works reliably but can reduce image quality slightly depending on your print settings. If quality matters, use Preview on Mac or a dedicated PDF tool instead.

Merging PDFs on Mac using Preview

Open the first PDF in Preview (the default PDF viewer on Mac). Go to View > Thumbnails to show a sidebar with page thumbnails. Open the second PDF in a new Preview window by pressing Cmd+O and selecting the file.

In the second window, select all pages by pressing Cmd+A, then drag them into the thumbnail sidebar of the first window. The pages will appear at the end of the first document. You can reorder them by dragging individual thumbnails up or down. When you're satisfied with the order, go to File > Export As, give the merged file a new name, and click Save.

Preview preserves image quality and works without installing anything. The only limitation is that you can only merge two or three PDFs comfortably this way before the interface becomes unwieldy.

Using free online tools to merge PDFs

Services like ILovePDF, Smallpdf, and PDF Merge let you upload multiple PDFs and download a combined file. Visit the website, click the upload button, select both PDFs from your computer, arrange them in the order you want, and click Merge or Combine. The result downloads to your Downloads folder within seconds.

Online tools work on any device—phone, tablet, or computer—and require no installation. The tradeoff is that your files are temporarily stored on someone else's server. Most reputable services use encryption and delete files after a few hours, but if your PDFs contain sensitive information, read the privacy policy first. ILovePDF and Smallpdf both offer free tiers with file size limits (usually 150 MB per file), and paid plans if you need to merge larger documents regularly.

Using Adobe Acrobat Pro for advanced merging

If you own Adobe Acrobat Pro, open it and go to File > Create > Merge Files. Click "Add Files," select both PDFs, and arrange them in the order you want. Acrobat shows a preview of each page, so you can see exactly what you're combining. Click Merge to create the combined file.

Acrobat Pro costs about $180 per year as part of Creative Cloud, or $15 per month month-to-month. It's worth the cost if you merge PDFs regularly, edit text within them, or need to compress large files. For occasional merging, the free alternatives above are usually sufficient.

Using free software like PDFtk for command-line merging

PDFtk is a free, open-source tool that runs from the command line on Windows, Mac, or Linux. Download it from pdftk.com, install it, and open Terminal (Mac) or Command Prompt (Windows). Navigate to the folder containing your PDFs and run a command like: pdftk file1.pdf file2.pdf cat output merged.pdf

This approach is faster than clicking through a graphical interface if you merge PDFs frequently. It also gives you precise control over which pages to include—you can merge only pages 1-5 from the first file and pages 10-15 from the second, for example. The learning curve is steeper than point-and-click tools, but the PDFtk documentation includes clear examples for common tasks.

Choosing the right method for your situation

Use Preview on Mac if you're merging two or three PDFs and want the fastest, simplest result. Use Microsoft Edge on Windows if you don't want to install anything new. Use an online tool like ILovePDF if you're on a phone or tablet, or if you need to merge more than three files at once. Use Adobe Acrobat Pro if you work with PDFs daily and need advanced features like compression or text editing. Use PDFtk if you merge PDFs regularly and don't mind typing commands.

The quality of the merged file is nearly identical across all these methods. The main differences are speed, convenience, and whether your files stay on your own computer or upload to a server. For a one-time merge of two simple PDFs, Preview or Edge is usually fastest. For regular work, invest in either Acrobat Pro or learn PDFtk.

Frequently Asked Questions

Will merging PDFs reduce the quality or file size?

Preview and PDFtk preserve quality and file size. Online tools and Microsoft Edge's print method may slightly reduce image quality or increase file size, depending on compression settings. If quality is critical, use Preview on Mac or PDFtk on any system.

Can I merge more than two PDFs at once?

Yes. Online tools and Adobe Acrobat Pro let you upload five or more files and arrange them in any order. Preview works but becomes slow with more than three files. PDFtk can merge unlimited files with a single command.

What if the PDFs have different page sizes or orientations?

All these methods will merge them as-is without resizing. If you need to standardize page sizes before merging, Adobe Acrobat Pro has built-in tools. Online services and PDFtk do not resize pages automatically.

Is it safe to upload PDFs to online merging tools?

Reputable services like ILovePDF and Smallpdf encrypt files during upload and delete them after a few hours. Read their privacy policy if your PDFs contain confidential information. For sensitive documents, use Preview, Edge, or PDFtk instead, since the files never leave your computer.

Can I merge PDFs on my phone?

Yes, using online tools. Open ILovePDF or Smallpdf in your phone's browser, upload both PDFs, and download the result. Some phones also have built-in PDF readers with merge features—check your phone's default PDF app or the app store for options specific to iOS or Android.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.