Every year we get requests on how to easily combine pdfs.
You can combine pdfs in the full version of Adobe Acrobat but if you don’t have that version there are cheap (free or low cost) alternatives.
For PCs: PDF Split and Merge does exactly what you hope it would do. Combine your pdfs. This article praises it and you’re able to download it for free here. Last we checked it looks like he regularly makes updates to this very useful utility so chances are good he will keep it updated.
For Macs: Combine PDF is without a doubt the best tool to combine pdfs on a Mac. I’ve used it for 4 years and its never let me down.
Both of these apps request that you donate but it is not a requirement for the software to work.