The simplest way to join PDFs depends on what you have on your computer
You can combine two PDF files using built-in tools on Windows or Mac, free online services, or dedicated PDF software. The fastest route for most people is a free online tool like ILovePDF or Smallpdf, which takes about two minutes. If you prefer not to upload files to the internet, your operating system has a native option: Preview on Mac, or the Print to PDF feature on Windows combined with a free tool like PDFtk or Ghostscript.
The method you choose depends on file size, how often you need to do this, and whether you want to keep files on your computer or use a web browser. None of these options cost money or require you to install software you'll use only once.
Key Takeaways
- Online PDF tools like ILovePDF, Smallpdf, and PDF Merge are free and require no installation, but they upload your files to their servers temporarily.
- Mac users can combine PDFs directly in Preview by opening one file, dragging the second into the sidebar, and exporting as PDF.
- Windows users can use free command-line tools like PDFtk or Ghostscript, or install free software like LibreOffice Draw to open and combine PDFs.
- If your PDFs contain sensitive information, keeping files on your computer rather than uploading them to a web service reduces the risk of exposure.
Using an online PDF tool (fastest for most people)
Online PDF combiners work in your web browser and don't require installation. Go to ILovePDF.com, Smallpdf.com, or PDFMerge.com, click the button to select or drag your two PDF files into the upload area, arrange them in the order you want, and click Merge or Combine. The tool processes the files on its servers and gives you a download link within seconds.
The trade-off is that your files are temporarily uploaded to someone else's server. Most reputable tools delete files automatically after a few hours, but if your PDFs contain sensitive information—tax returns, medical records, legal documents—this method carries a small privacy risk. Check the tool's privacy policy before uploading. ILovePDF and Smallpdf both state they delete files after a few hours and don't store them permanently.
This method works on any device with a web browser: Windows, Mac, Linux, tablet, or phone. No software installation needed.
Combining PDFs on a Mac using Preview
Mac's built-in Preview app can merge PDFs without any additional software. Open the first PDF in Preview, then open the second PDF in a new Preview window. In the first window, go to View menu and select Thumbnails to show a sidebar with page thumbnails. Drag the second PDF's pages from its window into the sidebar of the first PDF, positioning them where you want them. Go to File > Export As, name your new file, and save it as a PDF.
This keeps everything on your computer and is faster once you know the steps. The limitation is that Preview works only on Mac, and it can be slow if your PDFs have many pages.
Combining PDFs on Windows using free software
Windows doesn't have a built-in PDF merger like Preview, but you have two options. The easiest is to install LibreOffice Draw, which is free and open-source. Open the first PDF in Draw, go to Insert > Page from File, select your second PDF, and choose where to insert it. Save the result as a PDF.
If you prefer not to install software, you can use command-line tools like PDFtk or Ghostscript, but these require typing commands in Command Prompt or PowerShell and are slower for beginners. PDFtk has a graphical interface called PDFtk GUI that makes it easier, though it's less actively maintained than the command-line version.
For most Windows users, installing LibreOffice Draw is the most straightforward approach. Download it from LibreOffice.org, install it, and follow the steps above.
When to use each method
| Method | Best for | Time to complete | Privacy consideration |
|---|---|---|---|
| Online tool (ILovePDF, Smallpdf) | One-time jobs, any device, no installation | 2–3 minutes | Files uploaded to external server |
| Mac Preview | Mac users, sensitive files, frequent merging | 3–5 minutes | Files stay on your computer |
| Windows LibreOffice Draw | Windows users, sensitive files, frequent merging | 5–10 minutes (includes installation) | Files stay on your computer |
| Command-line tools (PDFtk, Ghostscript) | Advanced users, automation, batch processing | Varies | Files stay on your computer |
What to do if the merged PDF looks wrong
Sometimes merged PDFs have formatting issues: pages appear in the wrong order, text is cut off, or images are misaligned. This usually happens when the original PDFs were created with different settings or when the merging tool doesn't handle the PDF structure correctly.
If this happens, try a different tool. Online tools sometimes handle complex PDFs better than desktop software, or vice versa. If one method produces a corrupted result, test with another before assuming the file is damaged. Also check that you're merging the files in the correct order—it's easy to reverse them by accident.
Frequently Asked Questions
Can I merge more than two PDFs at once?
Yes. Online tools and desktop software both handle multiple files. Most online tools let you upload 5 to 20 files at once and arrange them in any order before merging. LibreOffice Draw and Preview can also insert multiple PDFs, though you may need to repeat the insert step for each file.
Will merging PDFs reduce the file quality?
No, merging doesn't compress or degrade the PDFs themselves. The merged file will be roughly the size of the two original files combined. Some tools offer optional compression, which reduces file size but may lower image quality slightly.
Is it safe to upload PDFs to online merging tools?
Reputable tools like ILovePDF and Smallpdf use encryption and delete files automatically after a few hours. However, if your PDFs contain highly sensitive information, keeping files on your computer using Preview or LibreOffice Draw eliminates the upload step entirely.
What if one of my PDFs is password-protected?
You'll need to remove the password first. Most online tools and desktop software can't merge password-protected PDFs without unlocking them. Use the same tool or a dedicated PDF unlocker to remove the password, then merge. If you don't know the password, you cannot unlock the file.
Can I merge PDFs on my phone or tablet?
Yes, using an online tool in your mobile browser. Upload both files, arrange them, and download the result. Some mobile apps like Adobe Acrobat Reader and PDF Expert also offer merging, though they may require a paid subscription for this feature.