The complete Java runtime for modern browsers

CheerpJ is a JVM and a distribution of OpenJDK for the browser in WebAssembly and JavaScript. Now supporting Java 8, Java 11 and Java 17 (preview), with Java 21+ coming in 2026.

Why CheerpJ?

Java Compatibility

Java Compatibility

Full support for Java 8, Java 11, and Java 17 (preview). Seamlessly migrate your Java applications to the browser.

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WebAssembly Performance

WebAssembly Performance

High-performance execution via WebAssembly. Experience near-native speeds for Java in the browser.

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Legacy Application Support

Legacy Application Support

Modernize legacy Java applications and applets for today’s browsers—no code rewrites needed.

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JavaScript Integration

JavaScript Integration

Seamless interoperability between Java and JavaScript. Integrate with modern web frameworks and APIs.

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Ratings and adoption

Teams choose CheerpJ to run Java securely and efficiently in the browser.

4.5/5 average rating

Based on user feedback and production deployments

Roadmap

What's Next for CheerpJ

Client Reviews

What People Think About Us