Once you’ve uploaded all your files, make sure they are Why you should combine your PDFs on a PC Free service to merge PDF. Merge PDF files. Follow these easy steps to combine PDF documents into one file: Click the Select a file button above or drag and drop files into the drop zone. This is an easy way to bring multiple PDFs together into one. Click Add Files or Add How to combine and merge your files into one PDF: Open Acrobat to combine files: Open the Tools tab and select Combine files. Add