| Open-source unit TESTING framework for writing test cases. | TestNG is similar to JUnit but with extended functionalities. |
| JUnit does not support advanced annotations. | This supports advanced and special annotations too. |
| JUnit does not support PARALLEL testing. | TestNG supports MULTIPLE threads to run parallelly. |
| Group test is not supported. | TestNG is supported in TestNG. |
| The naming CONVENTION for annotations like Before, After, Expected are confusing. | The naming convention for understanding annotations like BeforeMethod, AfterMethod, ExpectedException is easy to understand based on their functionality. |
| Cannot rerun FAILED cases. | Can rerun failed tests. |
