The best reason to convert a PNG to a PDF is that you want to include multiple image files within one file that can be viewed on any system. This is one reason why converting between the two formats might be useful. For example, you can upload a PNG to Instagram but you can’t upload a PDF. However, image files can be needed for other reasons. Image files aren’t great for documents because one file can’t have multiple pages. In fact, it will even look the same across operating systems, so a PDF from a MacBook will look the same on a Windows laptop. If you create a PDF on your smartphone, it will look the same on a laptop, and vice versa. The advantage of saving your documents in this format is that PDF files look the same on any screen. PDF files are documents that usually contain text, links, and sometimes images.
