Short for Small Web Format - also known as ShockWave file - SWF is an Adobe Flash format containing videos and vector animations. It was mainly used by Macromedia before being bought by Flash and it’s a format to deliver multimedia content on the internet with minimum resources and top security. Since it’s a mainly online format, you won’t be able to open SWF on Mac without a reliable player. Adding a SWF Player for Mac will enable you to watch any videos in this format and if you don’t want to install new software on your Mac, the only option is to convert SWF files to a different format.