Use Adobe Acrobat Pro:
Open Acrobat Pro
Select “Combine Files” (or “Create” > “Combine Files”)
Add your PDFs
Reorder pages/files as needed
Click “Combine”
Save the merged PDF
Use Preview (macOS):
Open the first PDF in Preview
Drag additional PDFs into the sidebar (or “Thumbnails” view)
Arrange pages/files in the desired order
Select “File” > “Export as PDF” (or “Save”)
Use Google Drive (web):
Upload all PDFs to Google Drive
Open a PDF in Google Drive and use it with a PDF merge tool (Google Drive doesn’t merge natively)
Use a third-party “merge PDF” web tool and upload the files
Download the merged PDF
Use Microsoft Edge (web):
Use a “PDF merge” web tool from the Edge browser
Upload PDFs to the tool
Merge and download the combined PDF
Use Smallpdf (web):
Go to the Smallpdf “Merge PDF” page
Upload PDFs
Drag to reorder
Click “Merge PDF”
Download the result
Use iLovePDF (web):
Open iLovePDF “Merge PDF”
Upload PDFs
Reorder if needed
Merge and download the combined file
Use PDFtk (command line):
Install PDFtk
Run: `pdftk file1.pdf file2.pdf cat output merged.pdf`
Use qpdf (command line):
Install qpdf
Run: `qpdf –empty –pages file1.pdf file2.pdf — merged.pdf`
Use Ghostscript (command line, simple concatenation):
Install Ghostscript
Run: `gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=merged.pdf file1.pdf file2.pdf`