Improving IDEA Maven Build Speed with Multi‑Threading and Build Cache

Background – Large projects with many modules suffer from long build times because IDEA uses its built‑in Maven, which runs in single‑thread mode and has limited configuration options.

Prerequisites – The method applies to projects developed with IntelliJ IDEA (tested on IDEA 2023.2) and Maven 3.8.6, but works with newer versions as well.

Reason IDEA builds are slow – IDEA’s bundled Maven executes tasks sequentially, and its configuration cannot be tuned for large projects, leading to low efficiency.

1. Enable multi‑threading

Open IDEA Settings → Build, Execution, Deployment → Build Tools → Maven and set the "Thread Count" to a multi‑thread mode (e.g., 10 threads based on your CPU).

2. Delegate IDE build/run to Maven

In the same Maven settings, check "Delegate IDE build/run to Maven" to let Maven handle the build process.

3. Add configuration files

To further optimise, add Maven extensions and cache configuration:

1. Create a .mvn directory at the project root.

2. Inside the .maven folder, add an extensions.xml file with the following content:

<extensions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/EXTENSIONS/1.0.0"
    xsi:schemaLocation="http://maven.apache.org/EXTENSIONS/1.0.0 http://maven.apache.org/xsd/core-extensions-1.0.0.xsd">
    <extension>
        <groupId>org.apache.maven.extensions</groupId>
        <artifactId>maven-build-cache-extension</artifactId>
        <version>1.1.0</version>
    </extension>
</extensions>

3. In the same .maven folder, add a maven-build-cache-config.xml file with the following content:

<?xml version="1.0" encoding="UTF-8"?>
<cache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/BUILD-CACHE-CONFIG/1.0.0"
    xsi:schemaLocation="http://maven.apache.org/BUILD-CACHE-CONFIG/1.0.0 https://maven.apache.org/xsd/build-cache-config-1.0.0.xsd">
    <configuration>
        <enabled>true</enabled>
        <hashAlgorithm>SHA-256</hashAlgorithm>
        <validateXml>true</validateXml>
        <remote enabled="false">
            <url>http://host:port</url>
        </remote>
        <local>
            <location>.build-cache</location>
            <maxBuildsCached>3</maxBuildsCached>
        </local>
        <projectVersioning adjustMetaInf="true"/>
    </configuration>
    <input>
        <global>
            <glob>{*.java,*.groovy,*.yaml,*.svcd,*.proto,*assembly.xml,assembly*.xml,*logback.xml,*.vm,*.ini,*.jks,*.properties,*.sh,*.bat}</glob>
            <includes>
                <include>src/</include>
            </includes>
            <excludes>
                <exclude>pom.xml</exclude>
            </excludes>
        </global>
        <!-- Additional plugin and execution configurations omitted for brevity -->
    </input>
</cache>

Conclusion – Applying these settings enables parallel builds, delegates the build process to Maven, and introduces a build‑cache extension, which together can dramatically reduce the time spent on Maven builds in IDEA. If you find this method helpful, consider giving it a like.