Awesome Open Source
Awesome Open Source


A small, extensible library to randomly mutate JSON documents, XML, HTML forms, text and binary data. Useful for fuzz testing.

Examples of things you can test by mutating known good input:

  • unexpected structures will not make your application code throw unchecked exceptions
  • your application code ignores additional fields
  • your application code does not throw unchecked exceptions when parsing values from JSON strings
  • your application does not instantiate arbitrary classes named in JSON data (a potential security risk)
  • and more!

See an interactive demonstration.

Download from Maven Central

  • Version 3.x.x.x (kotlin branch) is for Kotlin
  • Version 2.x.x.x (java8 branch) is for Java 8, and uses streams and Java 8 function types
  • Version 1.x.x.x (java7 branch) is for Java 7 and depends on Guava

Get A Weekly Email With Trending Projects For These Topics
No Spam. Unsubscribe easily at any time.
Javascript (1,538,296
Kotlin (58,493
Json (10,940
Testing (6,194
Xml (3,718
Form (2,142
Text (1,532
Jvm (1,035
Binary (969
Kotlin Library (751
Fuzzing (477
Test Driven Development (426
Related Projects