instancio/instancio

Health v2 · maintenance only

Adoption not part of the score

1159 stars · 68 forks observed · 2026-09-01

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

Instancio is a Java library that automatically creates fully-populated objects with random data for unit tests, including nested objects, collections, and generic types. It offers selective field overrides, reusable templates, reproducible seeds, and integrations with JUnit, Kotlin, Guava, and Protobuf.

Use cases

• generate test data for java unit tests
• populate nested objects automatically in tests
• create random test fixtures with junit
• reduce boilerplate test setup code
• generate reproducible random test data with seeds
• create lists of test objects in java
• generate test data from csv files

When to choose

• you write Java or Kotlin unit tests and want to eliminate manual test data setup
• you need fully-populated object graphs including nested objects, collections, and generics
• you want randomized inputs with reproducible seeds for debugging failures
• you use JUnit and want parameter-free tests with dynamic data

When to avoid

• you need realistic domain-specific data like valid addresses or names as the primary goal
• you work outside the JVM ecosystem
• your tests require exact, deterministic values for every field

Facets

library · maturity active

testing data-generation mocking testing developer-tools jvm test-data-generator junit unit-testing object-population random-data kotlin protobuf java

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