I have had success doing so with SuperNova SWF Enabler while using the Chrome browser. Use another player for playing flash files in browser. Im having issues using it with firefox though. Also some swf should extend to mobile devices because of that. Since its played in webassebly it cant be saved properly anymore (far as I know) and the flash security issues that supposedly existed in the past are fixed this way. The idea is it takes a flash file, loads it as webassembly, then plays it like normal with no loss of any kind. It is currently a work in progress and there are also several others doing more or less the same. Have sites that have not already update themselves to playback swfs as a different format like webassembly. The Flash player from adobe can be found here and is named Flash Player projector

A good one however can play most swf files more or less as originally intended. Each with their own quirks and incompatabilities. You can use a Standalone Flash / SWF Player so you can load your saved swf files in. Then play them offline. An attempt at murder happened but the will of the people decide.

Open swf on mac browser