Spring Boot starters are one of the most impactful productivity features of the framework.
They remove the need to manually select, version, and manage dozens of dependencies.

This post explains what starters are, how they work, and how to use them correctly in real-world Spring Boot applications.

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1. What Is a Spring Boot Starter?

A Spring Boot starter is a curated set of dependencies grouped together for a specific purpose.

Instead of adding multiple libraries manually, you add one starter.

Example:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

This single dependency pulls in everything required to build a web application.

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2. Why Starters Exist

Before Spring Boot, developers had to:

• Search for compatible library versions
• Manually manage transitive dependencies
• Fix version conflicts
• Maintain large pom.xml files

Starters solve these problems by providing:

• Opinionated dependency sets
• Guaranteed compatibility
• Clean and minimal build files

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3. What Does a Starter Contain?

A starter typically contains:

• Core Spring modules
• Third-party libraries
• Transitive dependencies
• Version alignment via Spring Boot BOM

Important:

Starters do NOT contain application code, only dependency definitions.

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4. Commonly Used Spring Boot Starters

Starter	Purpose
spring-boot-starter-web	REST & web apps
spring-boot-starter-data-jpa	JPA & Hibernate
spring-boot-starter-security	Security
spring-boot-starter-test	Testing
spring-boot-starter-validation	Bean validation
spring-boot-starter-actuator	Monitoring

Each starter focuses on one responsibility.

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5. Starter Internals (How They Work)

When you add a starter:

1. Maven/Gradle resolves the dependency
2. Transitive dependencies are pulled in
3. Auto-configuration detects libraries
4. Beans are registered automatically

Starters and auto-configuration work hand in hand.

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6. Dependency Version Management (BOM)

Spring Boot manages dependency versions using a Bill of Materials (BOM).

In Maven, this is handled by:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
</parent>

This ensures:

• Consistent versions
• No dependency conflicts
• Safe upgrades

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7. Using Starters with Gradle

Gradle example:

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
}

Gradle uses the Spring Boot plugin to apply the same version alignment.

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8. Custom Starters (Advanced Concept)

Organizations often create custom starters to standardize:

• Logging
• Security
• Observability
• Internal libraries

A custom starter typically includes:

• Auto-configuration classes
• Conditional beans
• Dependency definitions

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9. Common Mistakes with Starters

❌ Adding individual dependencies instead of starters

❌ Overriding versions unnecessarily

❌ Including unused starters

❌ Mixing incompatible Spring Boot versions

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10. Best Practices

• Prefer starters over individual dependencies
• Remove unused starters
• Trust Spring Boot’s dependency management
• Upgrade Spring Boot instead of individual libraries
• Use spring-boot-starter-test for testing

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11. Summary

• Starters simplify dependency management
• They bundle compatible libraries
• They work with auto-configuration
• They keep builds clean and maintainable
• They are essential for productivity

Understanding starters is key to building stable and scalable Spring Boot applications.

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What's Next?

Next post:

27 - Creating a Basic Application (Hands-on)

We’ll build a simple Spring Boot application step by step.