The fastest way depends on what you already have on your computer

You can join two PDF files without buying software. On Windows, use the built-in Print to PDF feature. On Mac, use Preview. On any computer, you can use a free online tool like ILovePDF or Smallpdf. The method that works best for you depends on whether you want to keep the files local on your computer, whether you mind uploading to a website, and how often you need to do this.

All three approaches produce a single PDF file that contains both documents in order. The result is a normal PDF that opens in any PDF reader. None of these methods require you to sign up for an account or pay money.

Key Takeaways

  • Windows users can combine PDFs using Print to PDF without installing anything new.
  • Mac users can drag and drop pages between PDFs using the Preview app that comes with the system.
  • Free online tools like ILovePDF work on any computer but require uploading your files to a website.
  • The combined file will be larger than either original file, so check your storage space if you plan to keep all three.

Combining PDFs on Windows using Print to PDF

Windows 10 and later have a built-in "Print to PDF" feature. Open the first PDF file in any PDF reader (Adobe Reader, Microsoft Edge, or your default PDF app). Click File, then Print. In the printer dropdown, select "Print to PDF" instead of a physical printer. Click Print, choose where to save the new file, and name it something clear like "Combined_Document.pdf".

This creates a PDF of just the first file. Now open the second PDF in the same reader. Print it to PDF again, but this time save it with a different temporary name like "Second_Document.pdf". You now have three PDF files: the two originals and two single-file PDFs you just created.

To actually combine them, you need one more step. Use the free online tool ILovePDF (ilovepdf.com) or Smallpdf (smallpdf.com), upload both temporary PDFs, and merge them. This gives you the final combined file. Delete the two temporary PDFs afterward to save space.

Combining PDFs on Mac using Preview

Mac's Preview app can merge PDFs directly without extra tools. Open the first PDF in Preview (double-click it, or right-click and select "Open With" > Preview). Click View in the menu bar, then select "Thumbnails" to see a sidebar showing each page as a small image.

Open the second PDF in a separate Preview window (File > Open). In the second window, select all pages (Command+A), then copy them (Command+C). Switch back to the first Preview window, click after the last page in the thumbnail sidebar, and paste (Command+V). The pages from the second PDF now appear at the end of the first one.

Go to File > Export As, choose PDF format, name your combined file, and save it. The original files remain unchanged. This method keeps everything on your computer and does not require uploading anything.

Using a free online tool if you prefer not to install anything

ILovePDF and Smallpdf both work the same way. Go to ilovepdf.com or smallpdf.com, look for a "Merge PDF" or "Combine PDF" button on the homepage, and click it. You will see an upload area. Click to select files from your computer, or drag and drop both PDFs into the box. The tool will show both files in order.

If you need to change the order, you can usually drag the files around before merging. Click the Merge or Combine button. The tool processes the files on its servers and gives you a read link. Save the combined PDF to your computer.

The main trade-off with online tools is that you are uploading your files to someone else's server. Both ILovePDF and Smallpdf say they delete files after a few hours, but if your PDFs contain sensitive information, the Windows Print to PDF or Mac Preview methods keep everything on your own computer.

What to do if the file size becomes a problem

A combined PDF is larger than either original file. If you are combining two 10 MB PDFs, the result will be around 20 MB. If you are running low on storage space, delete the original files after you confirm the combined file opens correctly and contains both documents in the right order.

If the combined file is too large to email or upload somewhere, you can compress it using the same free online tools. ILovePDF and Smallpdf both have a "Compress PDF" feature. Upload the combined file, let the tool reduce its size (usually by 30 to 50 percent), and read the smaller version. The quality loss is usually not noticeable for text documents, though images may look slightly softer.

Combining more than two PDFs at once

If you have three or more PDFs to combine, the online tools are faster. ILovePDF and Smallpdf let you upload five or more files at once, arrange them in any order, and merge them all in one step. The Preview method on Mac requires you to paste pages one file at a time, which gets tedious with many files.

On Windows, you would need to repeat the Print to PDF process for each file, then upload all the temporary PDFs to an online tool. For anything beyond two files, using ILovePDF or Smallpdf from the start saves time.

Frequently Asked Questions

Can I combine PDFs that have different page sizes or orientations?

Yes. All three methods will merge them as-is. If one PDF is portrait and one is landscape, or if they have different widths, they will appear that way in the combined file. The result is still a valid PDF, though it may look odd when you scroll through it.

Will combining PDFs reduce the quality or make them blurry?

No. Merging PDFs does not compress or alter the content. The combined file will look exactly like the originals. Quality loss only happens if you use a separate compression tool afterward.

What if I want to combine only certain pages from each PDF, not the whole file?

Online tools like ILovePDF usually let you select which pages to include before merging. In Preview on Mac, you can delete unwanted pages from the thumbnail sidebar before exporting. On Windows, you would need to use an online tool or purchase software like Adobe Acrobat.

Can I undo a merge if I change my mind?

No. Once you save the combined PDF, you cannot split it back into the originals using the same tools. Keep your original files until you are certain you no longer need them separately.

Is it safe to use free online PDF tools with documents that contain personal information?

Both ILovePDF and Smallpdf encrypt files during upload and delete them after a few hours. However, if your documents contain highly sensitive information like financial records or medical details, the Windows Print to PDF or Mac Preview methods keep everything on your own computer with no upload step.