What is the Minimum Java Version Required for Spring Boot 4?

Mar 5, 2026

I tried upgrading my Spring Boot 3.x application to Spring Boot 4 the other day, expecting a straightforward migration. I grabbed the latest dependency, ran my build, and immediately hit a wall. The compilation failed with cryptic errors about module resolution and class versions.

That was my first encounter with Spring Boot 4’s new Java requirement.

The Problem: Build Failures on Upgrade

When I attempted the upgrade, here’s what I saw:

[ERROR] module spring.core reads package javax.lang.model from hidden module
[ERROR] package javax.lang.model.util is hidden

This wasn’t a code issue - it was an environment problem. My project was still running on Java 11, which Spring Boot 4 simply won’t support anymore.

Why Java 17 is Now Mandatory

Spring Boot 4 made a deliberate choice to require Java 17 as the minimum version. Let me break down why this matters:

The Java Release Cadence

Java Version Timeline:
┌─────────────────────────────────────────────────────────────────┐
│  Java 8 (LTS)  │  Java 11 (LTS)  │  Java 17 (LTS)  │  Java 21  │
│      2014      │      2018        │      2021        │   2023    │
└─────────────────────────────────────────────────────────────────┘
                         ▲
                    Your old friend
                    (no longer supported)

Spring Boot 4 requires Java 17 for several compelling reasons:

Language Features: Records, sealed classes, and pattern matching make domain modeling cleaner
Performance: Improved garbage collectors and runtime performance
Module System: Full module system support for better encapsulation
Security: Latest security patches and improvements

Official Compatibility Range

According to the Spring Boot 4.0.3 documentation:

Version Type	Java Version
Minimum	Java 17
Maximum	Java 25
Recommended	Java 21/25

Checking Your Current Java Version

Before attempting any migration, I always verify my current Java setup:

java -version

On my machine, I saw something like:

openjdk version "17.0.16" 2024-07-16
OpenJDK Runtime Environment (build 17.0.16+8-b468)
OpenJDK 64-Bit Server VM (build 17.0.16+8-b468, mixed mode)

If you’re on Java 11 or below, you’ll need to upgrade first.

Configuring Your Build for Java 17

Once I figured out the Java version issue, I updated my build configuration. Here’s what worked for me:

Maven Configuration

<properties>
    <java.version>17</java.version>
    <maven.compiler.source>17</maven.compiler.source>
    <maven.compiler.target>17</maven.compiler.target>
</properties>

Gradle Configuration

java {
    sourceCompatibility = JavaVersion.VERSION_17
    targetCompatibility = JavaVersion.VERSION_17
}

Migration Strategy

Based on my experience, here’s the path I recommend:

Current Java → Target
─────────────────────
Java 8/11   → Java 17 → Java 21 → Spring Boot 4
                          ↓
                    Test thoroughly
                    before production

Don’t try to jump directly from Java 8 to Java 21 if you can avoid it - the language gap is significant and your code will need more adjustments.

Conclusion

The moment you attempt to upgrade to Spring Boot 4, you’ll need Java 17 at minimum. This isn’t a suggestion - it’s a hard requirement enforced at both compile time and runtime. I learned this the hard way, but now I always check my Java version before starting any Spring Boot 4 migration project.

The good news? Java 17 is a solid LTS release with excellent performance and modern language features that actually make your code cleaner. Once you make the jump, you won’t miss Java 11.

Final Words + More Resources

My intention with this article was to help others share my knowledge and experience. If you want to contact me, you can contact by email: Email me

Here are also the most important links from this article along with some further resources that will help you in this scope:

👨‍💻 Spring Boot 4 System Requirements

Oh, and if you found these resources useful, don’t forget to support me by starring the repo on GitHub!