How to Download and Use the Firefox Java Plugin Modern versions of Firefox (version 52 and later) do not support the required to run Java applets directly in the browser. As of 2026, Java applets have been officially removed from Java 26, ending the era of native in-browser Java execution.
If you absolutely require the original Java plugin for legacy compatibility, you must use an archived version of Firefox. download firefox java plugin
: While primarily featured for Chrome and Edge, similar tools like the JavaScript-Java Bridge extension exist for Firefox to facilitate communication between Java and JavaScript. 2. Using Java Web Start (JNLP) How to Download and Use the Firefox Java