OpenRewrite
Open-source automated refactoring ecosystem that eliminates technical debt through intelligent code transformations and migrations at scale
Overview
OpenRewrite is an open-source automated refactoring ecosystem designed to eliminate technical debt at scale by enabling developers to perform large-scale code transformations safely and reliably. The platform provides a library of pre-built "recipes" that can automatically update frameworks, migrate between versions, apply security patches, and modernize code patterns across entire repositories or organizations. Unlike simple find-and-replace tools, OpenRewrite uses semantic code analysis and type-aware transformations to ensure correctness, making it possible to perform complex refactorings that would be error-prone or impossible to do manually. The project is backed by Moderne, which offers commercial services for enterprise-scale code modernization.
The Verdict
Who Should Use OpenRewrite?
Best For
- Engineering teams managing large Java/Kotlin codebases with significant technical debt
- Organizations performing framework migrations (Spring Boot, JUnit, Java versions)
- Platform teams standardizing code patterns and best practices across repositories
- Security teams applying vulnerability patches and security fixes at scale
- Companies with microservices architectures requiring consistent updates across services
Not Ideal For
- Small projects where manual refactoring is manageable
- Languages other than Java, Kotlin, or Groovy (limited support for others)
- Teams without CI/CD infrastructure to integrate automated refactoring
What's Great
- Completely open-source with extensive library of pre-built refactoring recipes
- Type-aware transformations ensure correctness and prevent breaking changes
- Handles complex migrations like Spring Boot upgrades, Java version updates automatically
- Active community with weekly code remix sessions and comprehensive documentation
- Integrates with Maven, Gradle, and CI/CD pipelines for automated execution
Watch Out For
- Learning curve required to write custom recipes effectively
- Primarily focused on JVM languages, limited support for other ecosystems
- Some complex transformations may require manual review and adjustment
Pricing
View all features & details
Key Features
- 500+ pre-built refactoring recipes
- Type-aware code transformation engine
- Framework migration (Spring Boot, Quarkus, Micronaut)
- Java version upgrades (8 to 11, 11 to 17, etc.)
- Security vulnerability patching
- Custom recipe development with Java DSL
Supported Languages
- Java (primary)
- Kotlin
- Groovy
- XML, YAML, JSON (config files)
- Limited: Python, JavaScript (experimental)
How It Compares
| Feature | OpenRewrite | Semgrep | Sensei |
|---|---|---|---|
| Approach | Automated refactoring | Static analysis + autofix | IDE-based refactoring |
| Language Support | Java/Kotlin primary | 30+ languages | IntelliJ supported languages |
| Pricing | Free (OSS) | Free + Pro | Commercial |
| Best For | Large-scale migrations | Security scanning | Developer-guided refactoring |