Mozilla announced back in January 2013 that it planned to eventually require all plugins to be ‘Click to Play’ by default, meaning that users will need to click on plugins in-page in order to enable them and view their content.

Today, the company revealed it will close the application window for whitelisted plugins on March 31, but will only start blocking by default no sooner than Firefox 30. In a post on Mozilla’s security blog, the company said that it “strongly [encourages] site authors to phase out their use of plugins” due to new Web technologies that make plugins less essential and the effect they can have on browser stability.

Mozilla continued in the post to say that the change is also due to stability problems. The company said that “plugins are a significant source of poor performance, crashes and security vulnerabilities” and because of this “plugins present real costs to Firefox users.”

firefox click to play blocklist Mozilla to enable Click to Play by default for all plugins from March 31

Plugin developers have 30 days to submit a request to join a plugin whitelist, which will exempt them from the Click to Play changes and allow their plugins to load without user interaction.

Mozilla pointed out that the plugin whitelist is only temporary and will whitelist a single plugin for four consecutive Firefox releases.  After that, developers are encouraged to move away to Web-based technologies or will need to apply for a continued exemption.

Some plugins, such as Adobe Flash, will be permanently exempt from the Click to Play functionality but only for the very latest version of the player. Older versions will revert to requiring users to Click to Play or will require them to update the plugin.

Mozilla’s move is a good one; many plugins are bad for browser stability and performance, so requiring them to be disabled by default should lead to a more stable browsing experience for all.

Top Image Credit: Leon Neal/AFP/Getty Images