Run your Java applications in the browser

CheerpJ is real Java in the browser, built from OpenJDK. It runs your Java applets, Java Web Start applications and desktop Java applications in Chrome, Edge, Firefox and Safari, unmodified, so you can retire IE mode, the old browser or Citrix and keep the application. Find the page for what you run, what you want to replace and the industry you work in.

Browser extensions Talk to us

What CheerpJ is

  1. Built from OpenJDK. Runs in the browser.

    CheerpJ is a Java runtime built from OpenJDK and compiled to WebAssembly. It runs inside the browser tab, with the full Java class library, including Swing and AWT.

  2. Java 8, 11, 17, 21 and 25

    CheerpJ runs applications built for Java 8, 11, 17 and 21, with Java 25 in preview.

  3. Your application as it is

    CheerpJ runs the compiled application you already have, including third-party and obfuscated code, so the application and its server stay as they are.

  4. A browser extension or your own page

    A CheerpJ browser extension runs applets and Java Web Start applications in Chrome and Edge, from the pages that launch them today. CheerpJ served from your own web servers runs them in Chrome, Edge, Firefox and Safari.

  5. On the user’s computer, in the browser’s sandbox

    The application runs on the user’s computer under the browser’s security model, and reaches files and the network through browser APIs. There is no server component, and Enterprise deployments contact nothing, so CheerpJ runs on air-gapped networks.

I want to run

I want to replace

I work in

How I deploy

Build with Java for the browser.

Start building Run your Java app Talk to us