I will provide three free ways for you tobine PDFs on Mac. #1 Use Preview if you have not too many PDF documetns tobine. You can open one PDF in Preview and drag the other one directly to the thumbnails on the left side bar. #2 Use online service from PDF Merge Free Online This is a free online merger that you can merge PDF documents in the easiest way. Drop file and confirm the order. Thenbine them. #3 Use PDF Merge Split for Mac. PDF Merge Split for Mac is a easy to use Mac app to merge your PDF files. You can evenbine certain part of each PDF. What more it is not only a PDF Merger but also a PDF Splitter. It is free and you can download it from here .