The fastest way depends on what files you're starting with

The simplest method is to use your operating system's built-in PDF tools or free software that handles the file type you have. If you're combining Word documents, you can export them as PDFs and merge them in Windows or Mac's native tools. If you're starting with images, PDFs, or mixed file types, a free desktop program like PDFtk, ILovePDF, or Smallpdf will do the job in minutes without installing anything.

The time it takes depends on file size and how many you're combining — most merges finish in under a minute. You'll need all the files saved and accessible on your computer before you start, and you should know the order you want them in.

Key Takeaways

  • Windows 10 and 11 can merge PDFs using Microsoft Edge or the Print to PDF feature without downloading anything extra.
  • Mac users can drag PDFs into Preview, arrange them in the sidebar, and export as a single file.
  • Free online tools like ILovePDF and Smallpdf work in any browser but require uploading your files to their servers.
  • Desktop software like PDFtk and Ghostscript are free, keep files on your computer, and work with large batches.
  • The order of pages matters — arrange files before merging, not after.

Merging PDFs on Windows using built-in tools

Windows 10 and 11 include Microsoft Edge, which can open and combine PDF files without extra software. Open Edge, go to File > Open, and select your first PDF. Then open the second PDF in a new tab. Right-click the second tab and select "Print," then choose "Print to PDF" as your printer. In the print dialog, you can select which pages from the second PDF to include. Save the combined file with a new name.

This method works for two or three files but becomes tedious with more. For larger batches, use a dedicated tool instead. If you have Word documents you want to combine into a PDF, open each one in Word, then use File > Export as PDF for each, then merge the PDFs using the Edge method above.

Merging PDFs on Mac using Preview

Mac's Preview app handles PDF merging without downloading anything. Open Preview, then go to File > Open and select your first PDF. In the sidebar on the left, you'll see thumbnails of each page. Open your second PDF in a new Preview window (File > Open again), then drag the thumbnail of the second PDF's pages into the sidebar of the first window. Repeat for each additional PDF, arranging pages in the order you want them.

Once all pages are in the correct order in the sidebar, go to File > Export as PDF and save the combined file. This method is faster than Windows for multiple files because you can see all pages at once and rearrange them before saving.

Using free online tools for quick merges

ILovePDF and Smallpdf are browser-based tools that work on any computer without installation. Go to their websites, select "Merge PDF," then upload your files in the order you want them. Both tools let you drag files to reorder them before merging. Click the merge button, wait a few seconds, and download your combined PDF.

The trade-off is that your files are uploaded to their servers temporarily. Both services use encryption and delete files after a few hours, but if your PDFs contain sensitive information, a desktop tool is safer. These online tools are free for files under a certain size — usually 100 MB per file — and work well for occasional merging.

Using desktop software for large batches or sensitive files

PDFtk is free, open-source software that runs on Windows, Mac, and Linux. Download it from the PDFtk website, install it, then open the PDFtk GUI (graphical interface). Click "Add PDF" for each file you want to merge, arrange them in order using the up and down arrows, then click "Collate" and save. This method keeps all files on your computer and works with dozens of PDFs at once.

Ghostscript is another free option that runs from the command line — it's more technical but extremely fast for large batches. If you're comfortable with terminal commands, you can merge 50 PDFs in seconds. For most users, PDFtk's graphical interface is easier to learn.

Combining different file types into one PDF

If you're starting with a mix of Word documents, images, and existing PDFs, convert everything to PDF first, then merge. In Word, use File > Export as PDF. For images (JPG, PNG), use an online converter like CloudConvert or Zamzar, or use Preview on Mac to open the image and export as PDF. Once everything is a PDF, use any of the merging methods above.

Some online tools like ILovePDF accept multiple file types directly — you can upload a Word document, a JPG, and a PDF in one batch, and they'll convert and merge in one step. This is faster if you're only doing it once, but converting separately gives you more control over page size and quality.

Arranging pages and fixing common problems

The most common mistake is merging files in the wrong order. Always arrange them before you merge, not after — it's much faster. If you merged in the wrong order, you'll need to start over or use a PDF editor like PDFtk or Preview to delete unwanted pages and re-export.

If your merged PDF is much larger than expected, the original files may have high-resolution images. This is normal and doesn't affect readability on screen. If file size is a problem, use an online compression tool after merging. If pages appear out of order or rotated incorrectly, check that your source PDFs weren't already rotated — some tools preserve the original orientation even if it looks wrong.

Frequently Asked Questions

Can I merge PDFs on my phone or tablet?

Yes, but it's slower than a computer. On iPhone or iPad, use the free app "PDF Merger" or "Combine PDFs." On Android, try "PDF Merger" or "Merge PDF." These apps work the same way as desktop tools — upload or select your files, arrange them, and export. For occasional use it's fine, but for large batches, a computer is faster.

What if one PDF has the wrong page orientation?

Open that PDF in Preview (Mac) or PDFtk (Windows) before merging, select the rotated pages, and use the rotate button to fix them. Then export and merge with the others. Some PDFs are saved with the wrong orientation — fixing them first prevents the merged file from looking wrong.

Is it safe to use online PDF tools with confidential documents?

Most reputable tools like ILovePDF and Smallpdf encrypt files in transit and delete them after a few hours. If your documents contain passwords, social security numbers, or trade secrets, use a desktop tool like PDFtk instead, which keeps everything on your computer.

Can I merge PDFs and remove certain pages at the same time?

Most merging tools don't let you delete pages during the merge. Open each PDF in Preview or PDFtk, delete the unwanted pages, export, then merge the cleaned files. This takes a few extra minutes but gives you control over what ends up in the final file.

What's the file size limit for merging?

Online tools usually cap individual files at 100 MB to 500 MB depending on the service. Desktop tools like PDFtk have no practical limit — you can merge gigabytes of PDFs if your computer has enough memory. Check the website of whichever tool you choose for its specific limits.