Jazzer

Jazzer is a coverage-guided, in-process fuzzer for the JVM platform developed by Code Intelligence. It is based on libFuzzer and brings many of its instrumentation-powered mutation features to Java, Kotlin and other JVM-based languages.

Jazzer integrates with JUnit 5, so fuzz tests are written alongside regular unit tests with the jazzer-junit dependency, available on Maven Central for Maven and Gradle builds. It can also run as a standalone command-line fuzzer. Besides crashes, bug detectors report issues such as injections or deserialisation vulnerabilities. Jazzer is used by OSS-Fuzz to fuzz Java projects. It runs on Linux, macOS and Windows.

Jazzer is free and open source under the Apache 2.0 licence.