Java engine prototype

This page tests the engine Java Arena uses: the real javac 21 compiler and a Java virtual machine with the Java 21 class library, both running on this device. Your code is not sent anywhere.

Engine

Try it

Example Code (Main.java) Input for the program (stdin)

Phone benchmark

Measures how fast the engine is on this device: starting up, compiling, running, and stopping a program that never ends. It takes about a minute. Then tap Copy results and send them to the site's author.

About the engine

The compiler is OpenJDK's javac 21 compiled to WebAssembly with teavm-javac and TeaVM (Apache 2.0). Programs run on Ristretto, a Java virtual machine written in Rust (MIT or Apache 2.0), with the OpenJDK 21 class library (GPLv2 with the Classpath Exception). Everything is downloaded from this site once and then kept on your device, so it also works offline. Licenses and source code.