REST Assured

Open Source

Java DSL for testing and validating RESTful APIs.

Visit website GitHub

Pricing

Free / Open source

Type

Automation

Languages

Java

// VERDICT

Reach for REST Assured when your stack is Java and you want API tests as real code alongside your services. Skip it if your team is non-JVM or would be more productive in a GUI tool like Postman or a DSL like Karate.

Best for

Code-based API testing in Java with full programmatic control and a readable given/when/then syntax.

Avoid when

Your team isn't on the JVM, or testers prefer a GUI or a low-code DSL over writing Java.

CI/CD fit

GitHub Actions · GitLab CI · Jenkins · Maven · Gradle

Languages

Java

Team fit

Java/JVM teams · SDET teams · Backend-heavy QA teams

Setup

Medium

Maintenance

Medium

Learning

Intermediate

Licence

Free / Open source

// BEST FOR

Teams already building services in Java who want tests in the same language
API tests living in the codebase, versioned and reviewed like production code
Fine-grained control over requests, auth, serialisation and assertions
Integrating API checks into JUnit/TestNG suites and existing Maven/Gradle builds
Schema, header and payload validation with full programmatic flexibility
Combining API setup with UI tests in one Java framework

// AVOID WHEN

Your team or stack isn't on the JVM
Testers prefer a GUI for exploring and running requests
You want minimal-code tests via a DSL rather than writing Java
Manual testers without Java experience need to own the suite
You need built-in service virtualisation/mocks (Karate includes this)
A quick exploratory pass matters more than a maintainable code suite

// QUICK START

# Maven: add io.rest-assured:rest-assured to pom.xml, then
mvn test

// ALTERNATIVES TO CONSIDER

Tool	Choose it when
Karate	You want low-boilerplate API tests in a DSL with built-in mocks, instead of writing Java.
Postman	You want a GUI-first workflow to explore and test APIs before automating.

// MIGRATION NOTES

PostmanREST Assured

Moving from Postman collections to REST Assured trades a GUI for code: more upfront effort, but version-controlled, reviewable tests that run as part of your Java build. Port high-value collections first and keep Postman for exploratory work.