The simplest way to combine PDFs

The fastest way to merge two PDFs depends on what you already have on your computer. If you use Windows 10 or 11, you can do it without installing anything new — just open both files in Microsoft Edge, copy pages from one into the other, and save. On Mac, Preview (the built-in image viewer) lets you drag pages between PDFs. If you use a Chromebook or need more control over which pages go where, a free online tool like ILovePDF or Smallpdf takes about two minutes and requires no account.

The trade-off is straightforward: built-in tools are faster but less flexible. Online tools let you reorder pages, delete unwanted ones, or combine more than two files at once, but you upload your documents to someone else's server. For most people combining two straightforward documents, the built-in route is enough.

Key Takeaways

  • Windows 10 and 11 can merge PDFs through Microsoft Edge without downloading anything, by opening both files and copying pages between them.
  • Mac users can drag pages between PDFs using the Preview app, which comes installed on every Mac.
  • Free online tools like ILovePDF and Smallpdf work on any device and let you reorder pages before merging, but they require uploading your files to their servers.
  • Desktop software like Adobe Acrobat Reader (paid) or PDFtk gives you the most control but costs money or has a steeper learning curve.

Merging PDFs on Windows using Microsoft Edge

Open the first PDF in Microsoft Edge by right-clicking the file, selecting "Open with," and choosing Microsoft Edge. Once it opens, look at the toolbar on the right side of the window — you should see a pencil icon labeled "Edit PDF." Click it.

In Edit mode, look for the "Organize Pages" button in the toolbar (it looks like four squares). Click it to see thumbnails of all pages in your first document. Now open your second PDF in a new tab or window. Go back to your first PDF's Edit mode, and in the Organize Pages view, you can drag pages from one file into the other. When you are done, click "Save" and choose where to store the merged file.

This method works best when you want to keep all pages from both documents in order. If you need to delete pages, reorder them, or combine more than two files, the online tools below are faster.

Merging PDFs on Mac using Preview

Open the first PDF by double-clicking it — Preview opens automatically on Mac. Go to the menu bar and click "View," then select "Thumbnails" to see all pages as small images on the left side of the window.

Open your second PDF in a new Preview window (File > Open, or Command+O). Arrange both windows so you can see them side by side. In the second window, click on the first page you want to add, then hold Shift and click the last page if you want multiple pages. Drag those pages into the thumbnail panel of the first PDF. Preview will insert them at the end of the document. When you are done, save the first file (Command+S) — it now contains pages from both documents.

If you want to insert pages in the middle of your first document instead of at the end, click the page in the thumbnail panel where you want the new pages to go before dragging them over.

Using free online tools for more control

Go to ILovePDF.com or Smallpdf.com in any web browser. Both sites have a "Merge PDF" button on the home page. Click it, then click "Select PDF Files" and choose your first document from your computer. The site uploads it and shows you its pages as thumbnails.

Click "Add More Files" and upload your second PDF. You now see all pages from both documents in order. Drag any page to reorder it, or click the X on any page to remove it before merging. When the order is correct, click "Merge PDF" or "Combine" (the button name varies by site). The merged file downloads automatically to your Downloads folder.

These tools work on Windows, Mac, Chromebook, or any device with a web browser. The main drawback is that your PDFs travel across the internet to their servers. Most reputable sites delete files after a few hours, but if your documents contain sensitive information, the built-in Windows or Mac methods are safer.

When to use desktop software instead

If you regularly merge PDFs, reorder pages, or work with encrypted documents, desktop software saves time. Adobe Acrobat Reader (the paid version, not the free one) handles complex merging tasks and keeps everything on your computer. PDFtk is free and powerful but requires typing commands in a terminal window, so it is best for people comfortable with that approach.

For most people combining two or three documents occasionally, the free methods above are sufficient. Desktop software makes sense only if you do this work multiple times a week.

What to do if one PDF is password-protected

If your second PDF is locked with a password, you must unlock it before merging. Open it in Adobe Acrobat Reader (free version) or the online tool you are using, and enter the password when prompted. Some PDFs are locked to prevent editing but allow viewing and copying — those usually merge without extra steps. PDFs locked to prevent viewing require the password every time you open them.

If you have forgotten the password and own the document, contact whoever created it or locked it. If the PDF belongs to someone else, you cannot legally remove the password yourself.

Troubleshooting common problems

The merged file is much larger than expected: PDFs sometimes compress poorly when combined. Try using an online tool instead of your built-in method, or save the merged file as a new PDF from within your PDF reader — this often reduces file size.

Pages appear in the wrong order: You likely added them in the wrong sequence. Open the merged file in your PDF reader, look for an "Organize Pages" or "Edit" option, and drag pages into the correct order. Then save again.

Text or images look blurry after merging: This usually means one of your original PDFs was already low quality. The merge itself did not cause it. If both originals looked sharp, try merging them again using a different method — sometimes online tools handle compression differently than desktop software.

The online tool will not let me upload my file: Check the file size limit. Most free tools accept files up to 50 MB. If your PDF is larger, try compressing it first using an online PDF compressor, or use desktop software instead.

Frequently Asked Questions

Can I merge more than two PDFs at once?

Yes. Online tools like ILovePDF and Smallpdf let you upload as many files as you want and arrange them in any order before merging. Built-in tools like Windows Edge and Mac Preview require you to merge two at a time, then merge the result with a third file, and so on.

Will merging PDFs reduce the quality of the images inside?

Not usually. Merging straightforward combines the files without re-compressing them. However, if you save the merged file in a different format or use certain compression settings, quality can drop. Stick with PDF format when saving to preserve quality.

What if I only want to merge certain pages from each PDF, not all of them?

Online tools let you delete unwanted pages before merging. If you use built-in tools, merge the full files first, then open the result in your PDF reader and delete the pages you do not need.

Is it safe to upload my PDFs to an online merging tool?

Most reputable sites (ILovePDF, Smallpdf, PDF.io) delete files within hours and use encryption during upload. If your documents contain very sensitive information, use the Windows Edge or Mac Preview methods instead, which keep everything on your computer.

Can I undo a merge if I made a mistake?

The merged file is a new document — your original files are unchanged. If you do not like the result, delete the merged file and try again. Your originals are still there.