This free PDF merger can combine multiple PDF files into one PDF file, it combines all the pages in each file, joins them one by one and creates one big file for all the files, making it easier for you to share or read them. The order of which the files are merged is the order in which you enter them. In addition, you can select some image files as source files, such as JPG, BMP, GIF, PNG and more, these image files will be appended to the existing PDF document as new pages at the beginning or end of the output PDF document. You need to select at least two files, the third and fourth files are optional.
If there are more than 4 files, select the first 4 files and create an output file, then use the previously output file as the first file and attach the others.