Gradle Embraces Latest Java Development Kits for Performance Gains

Gradle, the widely-used build tool for Java projects, is aggressively adopting the latest Java Development Kits (JDKs) to improve performance, reduce resource consumption, and simplify maintenance. The practice, termed "Javamaxxing" by the development community, reflects Gradle's strategy of leveraging new JVM improvements while maintaining backward compatibility with older Java versions.

Gradle's approach to JDK adoption is systematic and rapid. The tool added daemon support for Java 24 in Gradle 8.14.0, Java 25 in version 9.1.0 (released just two days after JDK 25's general availability), and Java 26 in Gradle 9.4.0. This aggressive timeline allows Gradle to capture performance benefits from each new JDK release, including improvements to garbage collectors, compiler infrastructure, startup behavior, memory layout, and runtime APIs. The strategy does not force users to upgrade their project's target Java version; instead, the JVM toolchain feature introduced by Gradle fully separates the JVM running Gradle from the JVM compiling, testing, and executing user code.

Gradle has progressively raised its own minimum JDK requirements to align with industry support cycles. Gradle 9.0.0, released on July 31, 2025, increased the minimum JVM required to run the Gradle daemon to Java 17—the first such increase since Gradle 5.0 established Java 8 as the minimum in 2018. The roadmap includes further transitions: Gradle 9.6.0 deprecates daemon JVMs below Java 21, and Gradle 10.0.0 will require Java 21. This timeline aligns with Oracle's Java SE Support Roadmap, which marks the end of Premier Support for JDK 17 in September 2026.

Upgrading the JDK running Gradle often delivers measurable performance improvements without code changes. Newer JDKs provide features such as Compact Object Headers (JEP 519), which reduces object header sizes from 12 to 8 bytes on 64-bit platforms, potentially reducing heap usage by approximately 22 percent and CPU time by about 8 percent in benchmark workloads. Large Gradle builds managing millions of simultaneously active objects—including tasks, providers, file snapshots, dependency graphs, and configuration model objects—benefit substantially from such optimizations. Gradle also dynamically activates JDK-version-specific implementations internally, allowing the tool to use newer platform APIs without requiring all users to upgrade immediately.

Developers can experiment with performance features such as Compact Object Headers by configuring JVM arguments, though care must be taken to preserve existing heap and metaspace settings when doing so.