How to turn off Java applets

This article is no longer maintained, so its content might be out of date.

Support ended for all NPAPI plugins, except for Adobe Flash, in Firefox version 52. See this compatibility document and this article for details.

This article explains how to disable the Java plugin in Firefox so that Java applets no longer run.

By default, Firefox prompts you to activate Java when you visit websites with Java content. However, you may decide that you do not want Java applets to run. To disable Java applets in Firefox:

  1. Click the menu button Fx57menu , click Fx57Addons-icon Add-ons and select Plugins.
  2. Click on the Java(TM) Platform plugin Java Applet Plug-inJava plugin to select it.
  3. Select Never Activate in its drop-down menu if it's not already set.

Java applets will no longer be permitted to launch in Firefox and you will no longer be prompted to activate Java.

// These fine people helped write this article:AliceWyman, Chris Ilias, Michael Verdi, scoobidiver, Swarnava Sengupta, user669794, scootergrisen. You can help too - find out how.
Volunteer for Mozilla Support