Running Java applets in 2022 and beyond


Web browsers no longer support the Java plugin that allows applets to run in a browser. However, the CheerpJ Applet Runner extension for the Chrome (Chromium and Brave as well) web browser lets you run Java applets inside of the browser, without even having to install Java on your system. This can be done as follows:
  1. Install the CheerpJ Applet Runner Chrome extension. Once installed, the extension appears as a shield icon in the Chrome toolbar.
  2. When you visit a page with a Java applet, select the CheerpJ icon, then the extension will ask your permision to run the applet.
The CheerpJ extension works by 'converting' the Java Applet to WebAssembly and JavaScript on the fly. It is private and secure and does not collect any data or analytics. All your data, as well as your application, are kept within the boundaries of your browser. In my experience it works very well.