Mozilla Firefox To Begin Blocking Adobe Flash Plugin In August, Click-to-Play Arrives In 2017
Firefox isn't getting rid of Flash altogether, but the browser will begin blocking certain Flash content that Mozilla feels is not essential to the user experience. The decision to crack down on Flash plugins is one of several things Mozilla has planned to ultimately bring Firefox users improved security, better battery life, faster page loads, and better browser responsiveness.
"Browser plugins, especially Flash, have enabled some of our favorite experiences on the Web, including videos and interactive content. But plugins often introduce stability, performance, and security issues for browsers. This is not a trade-off users should have to accept," Mozilla stated in a blog post announcing the removal of some Flash plugins.

Mozilla's been slowly replacing various functionality previously offered only with plugins with web APIs. That includes things like audio and video playback, streaming capabilities, clipboard integration, faster 2D and 3D graphics, and more. Mozilla notes that as websites at large have switched from using Flash to other technologies, the plugin crash rate in Firefox has dropped dramatically. With plans to block more Flash content in the near future, Mozilla anticipates crashes due to Flash will drop another 10 percent.
Looking ahead to 2017, all Flash content will be click-to-play in Firefox. That means all Flash content will be blocked automatically, and you'll have to click on the Flash items you want to see or play with.