Mozilla recently announced that Firefox will “block certain Flash content that is not essential to the user experience”—in other words, ads and any behind the scenes operations using Flash. Mozilla says that blocking non-essential Flash should reduce crashes and browser hang-ups by as much as 10 percent. The initial blocked content will be restricted to a specific list that Mozilla has put up on Github, with plans to add more block targets to the list over time.
In 2017, Firefox will make all Flash content click-to-play by default. In other words, no Flash content will automatically start playing when you load a tab, including video and games. You'll have to manually authorize Flash content to start.
Why this matters: Flash was a crucial element to the web in its early days. Now, however, most if not all of its functionality can be replaced by native web technologies such as HTML5. Plus, NPAPI plugins like Flash are known to cause problems with browser stability, performance, and security. Even Adobe is moving away from Flash on the web. In late 2015, the company released a statement to “encourage content creators to build with new web standards,” which would inevitably lead developers away from Flash.
Firefox was the last major browser to give Flash a serious kick to the curb.
Google Chrome started pausing non-essential Flash content more than a year ago. Google also plans to make HTML5 the primary option for Chrome by the end of 2016, with only 10 sites white-listed to use Flash.
Microsoft followed Chrome’s lead with Edge in April. Apple, meanwhile, added click-to-play functionality to Safari 7 in 2013, and the upcoming Safari 10 on macOS Sierra will take a much harsher stand, telling websites that Flash isn’t installed on the user’s machine at all. This will force websites with an HTML5 option to use that instead—though Flash will still be available to users as a click-to-play option.
While Firefox is seriously reducing Flash's importance, Adobe's technology will remain as a plugin option for the foreseeable future. Similar to Chrome, Firefox will discontinue support for NPAPI plugins such as Java and Silverlight in March 2017, after pushing back original plans to end plugin support in late 2016. The only exception Flash.