Browser plugins have been sources of performance problems, crashes, and security incidents for Web users. By next year, Mozilla plans to make it possible for sites to switch away from plugins, as features that currently require plugins will be available via native Web APIs. Mozilla intends to remove support for most NPAPI plugins in Firefox by the end of 2016. Firefox began this process several years ago with manual plugin activation, allowing users to activate plugins only when they were necessary. This decision mirrors actions by other modern browsers, such as Google Chrome and Microsoft Edge, which have already removed support for legacy plugins. Moreover, since new Firefox platforms do not have to support an existing ecosystem of users and plugins, new platforms such as 64-bit Firefox for Windows will launch without plugin support.

Because Adobe Flash is still a common part of the Web experience for most users, Mozilla will continue to support Flash within Firefox as an exception to the general plugin policy.

Mozilla is collaborating with Unity to enable Unity-based content to be experienced directly in the browser without plugins. Unity has announced an updated roadmap for its Web Player technology.

Mozilla says that websites and publishers which currently use plugins such as Silverlight or Java should accelerate their transition to Web technologies.

Mozilla also works with the Oracle Java Platform Group to ensure a smooth transition for those web sites that use Java.