Posted 18 May 2017 - 04:24 PM
Do you mean an alternative to using the Flash Player itself to play Flash videos? Or do you mean an alternative to actually playing Flash videos on sites period?
If the latter, then there is not much you can do other that use what a site offers you. If they only offer Flash videos, then you are going to have play it as a Flash video. More and more sites are offering HTML5 instead or in addition to Flash.
If the former, I don't know of any other way to play Flash videos in Firefox other than downloading and installing the separate Adobe Flash plug-in. I could be wrong as I don't actively use Firefox much. Your only option would be to use Chrome, which includes its own built-in Flash support that Google updates along with Chrome...from what I recall at least.