A Mac and an iPhone can both merge PDFs with built-in tools. On Windows and Android, the easiest free route is a browser tool such as PDF24, which asks for no sign-up. Each system has its own steps, listed below, along with a few habits that keep your pages in the right order.
First, put all the files in one folder. Most “wrong order” mistakes start with files scattered around the device. If the document started as screenshots, our guide to screenshots on a PC shows how to capture them on Windows and Mac.
Mac: use Preview
Preview, the app that ships with macOS, merges PDFs by dragging pages. Here is Apple’s procedure:
- Open the PDFs you want to combine in Preview.
- In each one, choose View > Thumbnails to show the pages in the sidebar.
- Drag thumbnails from one PDF’s sidebar to the other’s. You can drop them at the end or between existing pages. To pick pages that aren’t next to each other, hold Command and click each one.
- To add a whole PDF, drag its icon from the Finder into the sidebar of an open document.
Preview saves changes automatically. If you want to keep the originals, choose File > Duplicate on each PDF before you start. To reorder pages later, drag the thumbnails around.
iPhone: use the Files app
You don’t need an extra app on iPhone. The Files app builds one PDF from several. These steps come from iGeeksBlog, a third-party site, so menu names can vary a little with your iOS version:
- Save the PDFs in the Files app, on the device or in iCloud Drive, in the same folder.
- Open the folder, tap the three dots at the top right, and choose Select.
- Check the PDFs you want to merge.
- Tap the three dots at the bottom right and choose Create PDF.
The new PDF appears in the same folder, usually named after the first file you selected, and the originals stay where they were.
Controlling the order on iPhone
According to the same source, files are combined in numerical or alphabetical order. When sequence matters, rename them first: “1 cover”, “2 contract”, “3 attachments”. It takes a minute and saves a redo.
Windows 11: a browser tool
On Windows, the free route is an online tool. Microsoft Edge’s PDF reader stays free for reading, but according to the Microsoft and Adobe announcement, features such as combining files belong to Acrobat, which is sold by subscription.
PDF24 runs in any browser (Edge, Chrome or another), with nothing to install. If the site hangs or loads wrong, clearing the browser cache usually fixes it. The steps:
- Open tools.pdf24.org/en/merge-pdf.
- Select your files in the box at the top or drag them into the marked area.
- Reorder the files by dragging and dropping if needed.
- Click the merge button and save the result as a single PDF.
The page says the service is free, needs no registration and is supported by ads. It gives no numeric limit on file size or count and describes itself as having “no limits.” If you prefer to work offline, PDF24 can also be installed as an app, which the site offers.
Android: the same site, in Chrome
PDF24 lists Android among its supported platforms, and it works in the phone’s browser. The steps match Windows: open the merge page in Chrome, pick the files from your phone, adjust the order and save the final PDF. The page also lets you install PDF24 as an app.
The wording of the file picker differs between phone brands, but the flow is the same: tap the selection area, choose the PDFs from Downloads or another folder, and confirm.
Before you use a website to merge PDFs
Online tools upload your file to a server. According to PDF24, transfers use SSL, its servers are in Germany, and files are deleted automatically after one hour. That is a reasonable policy for a school assignment or a utility bill, but not for everything.
Documents that must not circulate, such as contracts, medical results, bank statements, a driver’s license or a Social Security card, belong in the local route: Preview on a Mac, the Files app on an iPhone, or a program installed on your computer that works offline.
Checks before you send it
- Page order. Scroll through the whole PDF. A page out of place is the most common slip.
- Orientation. Pages from photos taken sideways can show up rotated. On a Mac, Preview lets you rotate a page.
- File name. The result often inherits the name of the first PDF. Rename it before sending.
- Originals. Keep the source PDFs until you are sure the final file is right.
Frequently asked questions
Does merging PDFs reduce quality?
None of the tools covered here report quality loss when merging. Still, compare the result with the originals before you send it.
Can I merge PDFs without internet?
Yes. Mac and iPhone do it locally, and PDF24 offers an installable version. Browser tools need a connection.
Do the original PDFs disappear after merging?
In the iPhone Files app, the originals stay where they were. On a Mac, Preview saves changes automatically to the file you are editing, so duplicate it first if you want an untouched copy.
Can I merge PDFs for free on Windows?
Yes, with a free online tool such as PDF24. Acrobat, which offers the feature inside Edge, is a paid subscription.
