Bxdty

Is there a way to run a Java applet on Chrome or Firefox? I get the error message on the Java test page (https://www.java.com/en/download/installed.jsp) that Java won't run on Chrome or Firefox anymore because of the non-supported NPAPI - https://www.java.com/en/download/faq/firefox_java.xml).

I have an old set of *.class files with a .html to run it, and I just want to be able to run this applet somehow. But how?

Is there a way to run a Java applet on Chrome or Firefox?

No. Applets are no longer supported in Firefox or Chrome.

Firefox no longer provides NPAPI support (technology required for Java applets)

As of September, 2018, Firefox no longer offers a version which
supports NPAPI, the technology required to run Java applets. The Java
Plugin for web browsers relies on the cross-platform plugin
architecture NPAPI, which had been supported by all major web browsers
for over a decade. The 64 bit version of Firefox has never supported
NPAPI, and Firefox version 52ESR is the last release to support the
technology. It is below the security baseline, and no longer
supported.

Source Java and Firefox Browser

Chrome no longer supports NPAPI (technology required for Java applets)

The Java Plugin for web browsers relies on the cross-platform plugin architecture NPAPI, which had been supported by all major web browsers for over a decade. Google's Chrome version 45 and above have dropped support for NPAPI, and therefore Java Plugin do not work on these browsers anymore.

Source Java and Google Chrome Browser

So how do I run Java applets?

Use the AppletViewer.

The appletviewer command allows you to run applets outside of a web
browser.

SYNOPSIS

appletviewer [ options ] urls ...

DESCRIPTION

The appletviewer command connects to the documents or resources
designated by urls and displays each applet referenced by the
documents in its own window. Note: if the documents referred to by
urls do not reference any applets with the OBJECT, EMBED, or APPLET
tag, then appletviewer does nothing. For details on the HTML tags that
appletviewer supports, see AppletViewer Tags.

Note: The appletviewer is intended for development purposes only.

Source appletviewer - The Java Applet Viewer

Alternatively read the Oracle White Paper (pdf) Migrating from Java Applets to plugin free Java technologies, which recommends Java Web Start:

Java Web Start has been included in the Oracle JRE since 2001 and is
launched automatically when a Java application using Java Web Start
technology is downloaded for the first time. The conversion of an
applet to a Java Web Start application provides the ability to launch
and update the resulting application without relying on a web browser

See What is Java Web Start and how is it launched? for more information.

If you already have the files on your machine, you can try the appletviewer that (used to? still does?) ships with the JDK (Java Development Kit).