Combining multiple PDFs into a single file is one of the simplest ways to cut down on digital clutter and make sharing documents easier. Managing separate files for reports, invoices, or receipts adds up quickly, and merging them into one solves that directly. Depending on your device and how much control you want over the process, you can do this with an online tool or a built-in desktop application. Here’s how to do it either way.

Method 1: Using a Free Online Tool

If you’re working from a mobile device, a Chromebook, or just want a fast option without digging into application settings, an online tool is the simplest route. A free tool to merge PDF pages into one file, like Adobe Acrobat’s online merge tool, processes everything directly in your browser:

1. Upload your files: Open the tool in your browser, then click Select Files or drag and drop the PDFs you want to combine into the upload area.
2. Arrange the pages: Once the files upload, you’ll see a thumbnail for each document. Drag them into the order you want the final file to read in.
3. Remove anything you don’t need: Hover over a file to delete or rotate individual pages before finalising.
4. Merge the files: Click Merge (or Combine), and the tool combines everything into a single PDF in a few seconds.
5. Download the result: Click Download to save the merged file, or sign in to generate a shareable link instead.

Method 2: Using a Built-in Tool on Your Desktop

You don’t always need new software to combine files locally. On a Mac, Preview has a built-in way to do this:

1. Open the first PDF: Double-click it to open it in Preview.
2. Turn on thumbnails: Go to View > Thumbnails to show a sidebar of page previews.
3. Choose where the new pages go: Click the thumbnail for the page you want the next document inserted after.
4. Insert the second file: Go to Edit > Insert > Page from File, then select the second PDF and click Open.
5. Reorder and save: Drag thumbnails in the sidebar if you need to reorder anything, then go to File > Export as PDF to save the combined document.

Windows doesn’t have an equivalent built-in tool for this, so Method 1 above is the more reliable option if you’re working on a PC.

The Bottom Line

Whether you merge files on your desktop or through a browser, combining related PDFs into one document makes them easier to store, find, and share. For most people, especially on Windows or a shared device, a free online merge tool is the simpler and more consistent option of the two.