Top 24 Open Source Alternatives to TestNG

Introduction

TestNG is a long-standing testing framework for the Java Virtual Machine (JVM) created by Cédric Beust in the mid-2000s. Inspired by JUnit and NUnit, it introduced a richer set of capabilities such as flexible annotations (e.g., @Test, @BeforeSuite), test grouping, data providers, dependency management, and robust parallel execution. These features made it popular across enterprise Java teams for unit, integration, and end-to-end automation—often in combination with Selenium for UI testing. TestNG’s XML-based suite configuration, listener model, and seamless integration with Maven/Gradle and major IDEs (IntelliJ IDEA, Eclipse) further boosted adoption.

Despite its strengths, testing has evolved beyond the JVM and unit/integration boundaries. Teams now automate web, mobile, APIs, performance, security, accessibility, and visual regressions across multiple languages and platforms. This shift has led many teams to explore alternatives that better match domain-specific needs, simplify test authoring, or provide batteries-included tooling for modern CI/CD.

This guide reviews top open source alternatives to TestNG, spanning UI, mobile, API, performance, security, accessibility, and even mutation testing. The goal is to help you choose the right tool for your context while acknowledging TestNG’s continued value in JVM-centric test automation.

Overview: 24 Top Open Source Alternatives to TestNG

Here are the top 24 alternatives for TestNG:

• Appium

• Citrus

• EarlGrey

• Espresso

• Gauge

• Geb

• JMeter

• Karate

• Lighthouse CI

• OWASP ZAP

• PIT (Pitest)

• Paparazzi (Cash App)

• Playwright

• Playwright Test

• Puppeteer

• Rest Assured

• Robot Framework + SeleniumLibrary

• Selenide

• Selenium

• Shot

• Spock

• Stryker

• Taiko

• xUnit.net

Why Look for TestNG Alternatives?

• Cross-platform and cross-language needs: Teams working in JavaScript, .NET, Python, or mixed stacks may prefer tools that are native to those ecosystems.

• Specialized testing domains: Performance, security, accessibility, and visual testing often require dedicated frameworks with domain-specific capabilities.

• Built-in tooling and simplified setup: Some modern frameworks include browsers, auto-waiting, tracing, and rich reporters out of the box, reducing boilerplate and flakiness.

• Readable or behavior-oriented specs: Teams favoring BDD-like or human-readable test formats may choose tools that embrace specification-style testing.

• Mobile-first automation: Native testing stacks for Android and iOS can offer tighter platform integration and more stable UI automation than JVM-based tools layered with drivers.

• Test quality assessment: Mutation testing tools can help evaluate the effectiveness of existing tests beyond coverage metrics.

Detailed Breakdown of Alternatives

1) Appium

What it is and who built it: Appium is an open source mobile automation framework maintained by a large community. It automates native, hybrid, and mobile web apps on iOS and Android using the WebDriver protocol.

What makes it different: Cross-platform mobile automation with one API and a large ecosystem of drivers and plugins.

Core strengths:

• Cross-platform (iOS, Android, mobile web) under one umbrella.

• WebDriver-based, familiar to Selenium users.

• Strong ecosystem and community support.

• Works with multiple languages and test runners.

• CI/CD friendly and widely documented.

Compared to TestNG: TestNG is a test runner and framework for the JVM; Appium focuses on device automation. You can still run Appium tests using TestNG in Java, but Appium is the better choice when your primary need is mobile UI automation rather than test orchestration alone.

2) Citrus

What it is and who built it: Citrus is an open source integration testing framework from the community, often associated with message-driven systems (HTTP, SOAP, JMS, and more).

What makes it different: It targets message-based and enterprise integration testing with a focus on verifying communication over various protocols.

Core strengths:

• Rich support for HTTP/REST, SOAP, JMS, and other protocols.

• Clear modeling of request/response and message validation.

• Suited for enterprise integration testing scenarios.

• Extensible with custom endpoints and data.

Compared to TestNG: TestNG can structure and orchestrate tests, but Citrus provides domain-specific helpers for messaging protocols. For integration-heavy, message-based systems, Citrus can reduce boilerplate that would be cumbersome in TestNG alone.

3) EarlGrey

What it is and who built it: EarlGrey is Google’s open source iOS UI testing framework.

What makes it different: It integrates tightly with iOS app lifecycles and synchronization, offering a stable approach to iOS UI automation.

Core strengths:

• Native iOS integration with automatic synchronization.

• Works well with Swift/Objective-C apps.

• Good stability for iOS UI interactions.

• CI-friendly and used in production-grade setups.

Compared to TestNG: TestNG does not drive iOS UIs. For iOS-native testing, EarlGrey gives more reliable synchronization and platform support. If your stack is JVM-only, EarlGrey requires working in iOS-native languages and tools.

4) Espresso

What it is and who built it: Espresso is Google’s official UI testing framework for Android.

What makes it different: Tight integration with Android, offering automatic synchronization with the UI thread for stable and reliable tests.

Core strengths:

• Official support from Google and Android tooling.

• Automatic waits and synchronization reduce flakiness.

• Integrates with Android Studio and Gradle.

• Fast execution on emulators and devices.

Compared to TestNG: TestNG does not provide Android UI automation. Espresso excels at native Android UI tests. If you need mobile UI tests in the Java ecosystem, Espresso is often more stable and integrated than layering TestNG + Appium.

5) Gauge

What it is and who built it: Gauge is an open source test automation framework from ThoughtWorks that emphasizes readable, specification-like tests.

What makes it different: It focuses on human-readable specs with cross-language support and a plugin ecosystem.

Core strengths:

• BDD-like, readable specification files.

• Multi-language support (e.g., Java, JavaScript, C#).

• Good plugin ecosystem and reporting.

• CI-friendly and modular.

Compared to TestNG: TestNG uses annotations and Java; Gauge provides more human-readable specs across multiple languages. If you need stakeholder-friendly test specs with decent tooling, Gauge may be more approachable.

6) Geb

What it is and who built it: Geb is a Groovy-based browser automation framework that combines WebDriver with a concise DSL, commonly used with Spock.

What makes it different: A succinct DSL for web automation, leveraging Groovy’s expressiveness.

Core strengths:

• Expressive Groovy DSL simplifies page objects and flows.

• Integrates well with Spock and JVM tooling.

• Strong WebDriver support with concise syntax.

• Good for teams already using Groovy.

Compared to TestNG: TestNG provides structure; Geb provides a testing DSL for browser automation. If your team prefers Groovy and concise web test code, Geb can be more productive than vanilla WebDriver with TestNG.

7) JMeter

What it is and who built it: Apache JMeter is a mature open source tool for performance and load testing across web, APIs, and various protocols.

What makes it different: It focuses on load, stress, and performance testing with GUI and CLI modes.

Core strengths:

• Broad protocol support and extensibility.

• Scalable load testing with distributed execution.

• Integrates with monitoring and APM tools.

• Mature community and documentation.

Compared to TestNG: TestNG is not a load testing tool. For performance engineering, JMeter is the better fit. You can still orchestrate JMeter in CI alongside TestNG, but JMeter owns the performance testing domain.

8) Karate

What it is and who built it: Karate is an open source test framework created by the community for API testing, with additional capabilities for UI via Playwright/WebDriver.

What makes it different: A DSL that unifies API testing, data-driven testing, and optional UI testing in one framework.

Core strengths:

• Simple DSL for REST and SOAP APIs.

• Data-driven testing and assertions built in.

• Optional UI testing via Playwright/WebDriver.

• Strong reporting and CI integration.

Compared to TestNG: TestNG provides structure; Karate provides a domain-focused DSL that reduces boilerplate for API tests. If you want a unified approach for API (and some UI) with minimal code, Karate can be more efficient.

9) Lighthouse CI

What it is and who built it: Lighthouse CI is an open source tool from the community (originating from Google’s Lighthouse) for automated audits of performance, accessibility, SEO, and best practices on the web.

What makes it different: Automated audits with scoring and thresholds you can enforce in CI.

Core strengths:

• Built-in audits for performance and accessibility.

• Thresholds and assertions to catch regressions.

• Works headlessly in CI pipelines.

• Actionable scoring for web quality.

Compared to TestNG: TestNG doesn’t provide web audits. Lighthouse CI augments functional tests with quality metrics. Use Lighthouse CI when you need automated performance and accessibility checks, not just pass/fail functional outcomes.

10) OWASP ZAP

What it is and who built it: OWASP ZAP is an open source dynamic application security testing (DAST) tool from the OWASP community.

What makes it different: Actively scans web apps and APIs to find common security issues.

Core strengths:

• Automated scanning for security vulnerabilities.

• Good for baseline DAST in CI/CD.

• Active and passive scanning modes.

• Strong community and add-ons.

Compared to TestNG: TestNG does not conduct security scans. ZAP is a dedicated security tool to complement functional testing, fitting teams that want continuous baseline security checks.

11) PIT (Pitest)

What it is and who built it: PIT is an open source mutation testing tool for JVM languages.

What makes it different: It mutates bytecode to measure how effectively your tests catch faults.

Core strengths:

• Objective measure of test quality beyond coverage.

• Integrates with Maven/Gradle.

• Detailed reports on surviving mutants.

• Encourages stronger assertions and test design.

Compared to TestNG: TestNG runs tests; PIT evaluates test effectiveness. Use PIT alongside TestNG (or other runners) to improve test suites, especially for critical codebases.

12) Paparazzi (Cash App)

What it is and who built it: Paparazzi is an open source library from the Cash App (Square) team for Android screenshot testing without an emulator.

What makes it different: It runs screenshot tests on the JVM without spinning up an Android emulator, speeding feedback.

Core strengths:

• Fast, emulator-free screenshot testing.

• Good fit for UI component libraries and visual regression.

• Deterministic rendering for stable snapshots.

• CI-friendly and resource-efficient.

Compared to TestNG: TestNG doesn’t do screenshot diffs. Paparazzi is specifically for Android visual regression. Use it to catch UI regressions quickly in Android pipelines.

13) Playwright

What it is and who built it: Playwright is an open source browser automation framework from the community with contributions originally from Microsoft.

What makes it different: First-class, cross-browser automation (Chromium, Firefox, WebKit) with auto-waits, tracing, and robust tooling.

Core strengths:

• Cross-browser with consistent APIs.

• Auto-waiting for stability and less flakiness.

• Trace viewer, screenshots, and videos built in.

• Multi-language support (Java, Python, .NET, Node.js).

Compared to TestNG: TestNG isn’t a browser automation engine. Playwright is a modern E2E framework with batteries included. You can use Playwright with its own runner or integrate with other runners, but it replaces a lot of glue code typically needed with TestNG + Selenium.

14) Playwright Test

What it is and who built it: Playwright Test is the official test runner for Playwright.

What makes it different: A purpose-built runner with parallelization, retries, fixtures, reporters, and built-in tracing.

Core strengths:

• Native integration with Playwright features.

• Parallelization and sharding out of the box.

• Rich reporters and artifacts (traces, videos).

• Intuitive test fixtures and configuration.

Compared to TestNG: TestNG is a general runner for Java; Playwright Test is a specialized runner for browser automation, especially in JavaScript/TypeScript. If your primary need is UI E2E in the JS/TS ecosystem, Playwright Test is more streamlined.

15) Puppeteer

What it is and who built it: Puppeteer is an open source Node.js library from the community that controls Chrome/Chromium via the DevTools Protocol.

What makes it different: Direct control of Chromium, ideal for headless browser automation and scraping.

Core strengths:

• Tight integration with Chromium.

• Great for automation, scraping, and PDF generation.

• Fast and scriptable in Node.js.

• Active community and ecosystem.

Compared to TestNG: TestNG provides structure in Java, while Puppeteer is a Node.js-first browser automation toolkit. For teams working in JS and targeting Chromium specifically, Puppeteer can be simpler and faster to adopt.

16) Rest Assured

What it is and who built it: Rest Assured is an open source Java DSL for testing REST APIs, created by the community.

What makes it different: Fluent, readable Java DSL that simplifies HTTP requests and assertions.

Core strengths:

• Concise API testing in Java.

• Easy assertions for status, headers, and payloads.

• Good JSON/XML support and schema validation.

• Integrates smoothly with JVM build tools and CI.

Compared to TestNG: TestNG is a runner; Rest Assured provides the fluent API testing layer. Many teams use Rest Assured with TestNG, but if API testing is your focus, Rest Assured reduces boilerplate significantly compared to plain HTTP clients under TestNG.

17) Robot Framework + SeleniumLibrary

What it is and who built it: Robot Framework is an open source, keyword-driven automation framework with a broad plugin ecosystem. SeleniumLibrary adds browser automation.

What makes it different: Keyword-driven style lowers the barrier for non-developers and supports extensive libraries beyond web (APIs, databases, etc.).

Core strengths:

• Keyword-driven tests readable by wider audiences.

• Large ecosystem (libraries for web, API, databases, etc.).

• Good reporting and log artifacts.

• Works well in CI/CD and across platforms.

Compared to TestNG: TestNG is code-centric for Java; Robot is keyword-centric and language-agnostic. If you want less code and a broader ecosystem, Robot Framework can be more accessible for cross-functional teams.

18) Selenide

What it is and who built it: Selenide is an open source Java framework that wraps Selenium WebDriver with a fluent API and smart waits.

What makes it different: It abstracts away synchronization and boilerplate common in Selenium tests.

Core strengths:

• Fluent, compact Java API for web UI tests.

• Implicit waits reduce flakiness.

• Easy screenshots and reporting.

• Integrates with JUnit/TestNG and CI tools.

Compared to TestNG: TestNG orchestrates tests; Selenide simplifies web automation code. Many teams pair Selenide with TestNG, but Selenide alone tackles a major pain point—synchronization—more effectively than vanilla WebDriver.

19) Selenium

What it is and who built it: Selenium is the de facto open source browser automation suite, maintained by the Selenium project and community.

What makes it different: Standard WebDriver protocol with bindings for multiple languages and broad browser vendor support.

Core strengths:

• Broad browser support and vendor alignment.

• Multi-language bindings (Java, Python, JS, C#, Ruby).

• Huge community and ecosystem (Grid, IDE, etc.).

• Flexible architecture and integrations.

Compared to TestNG: TestNG is often used with Selenium in Java. Selenium provides browser automation; TestNG provides the test structure. If you need cross-language support or want to avoid Java-only setups, Selenium with another runner (e.g., JUnit, pytest, Mocha) can be more flexible.

20) Shot

What it is and who built it: Shot is an open source Android screenshot testing tool from the community, focused on validating UI regressions.

What makes it different: It specializes in screenshot comparison for Android views and screens.

Core strengths:

• Purpose-built for Android visual regression.

• Works with Android development workflows.

• Helps catch pixel-level UI changes.

• CI-friendly validation and baselines.

Compared to TestNG: TestNG does not offer visual diffs. Shot focuses on the visual layer for Android, complementing functional tests by detecting appearance regressions earlier.

21) Spock

What it is and who built it: Spock is an open source testing framework for the JVM using Groovy, known for BDD-style, highly readable tests.

What makes it different: Expressive, specification-like structure with powerful data-driven testing and mocking.

Core strengths:

• Readable, behavior-driven specifications.

• Powerful data tables for parameterization.

• Built-in mocking/stubbing.

• Tight integration with Groovy and JVM builds.

Compared to TestNG: Both run on the JVM, but Spock’s DSL is more expressive and behavior-focused than TestNG’s annotation style. For teams that value readability and data-driven clarity, Spock is a strong alternative.

22) Stryker

What it is and who built it: Stryker is an open source mutation testing platform with implementations for multiple ecosystems (JavaScript/TypeScript, .NET, Scala).

What makes it different: Cross-ecosystem mutation testing to assess test suite effectiveness.

Core strengths:

• Objective quality metrics across stacks.

• Integrations with popular test runners.

• Detailed mutant reports to guide improvements.

• Encourages better assertions and coverage.

Compared to TestNG: TestNG is a runner; Stryker evaluates test strength by injecting faults. Use Stryker when you want continuous feedback on test quality, especially outside the JVM.

23) Taiko

What it is and who built it: Taiko is an open source Node.js browser automation framework from ThoughtWorks, emphasizing readable APIs.

What makes it different: A clean, readable approach to Chromium automation with sensible defaults.

Core strengths:

• Simple, readable Node.js APIs.

• Smart selectors and auto-waiting.

• Good for quick, maintainable E2E tests.

• CI-friendly with helpful diagnostics.

Compared to TestNG: TestNG is Java-first and not a browser automation engine. For teams standardizing on Node.js, Taiko offers a lightweight, readable alternative for browser tests without Java boilerplate.

24) xUnit.net

What it is and who built it: xUnit.net is a modern, open source unit testing framework for .NET, created and maintained by the community.

What makes it different: It embraces .NET conventions with an attribute-based model and strong integration with the .NET ecosystem.

Core strengths:

• First-class .NET developer experience.

• Strong integration with IDEs and build tools.

• Parameterized tests and extensibility.

• Large community and ecosystem.

Compared to TestNG: xUnit.net serves the .NET world much as TestNG serves the JVM. If your team is on .NET, xUnit.net is a natural fit over JVM-based frameworks.

Things to Consider Before Choosing a TestNG Alternative

• Project scope and domain: Identify whether you need unit, integration, E2E UI, mobile, API, performance, security, accessibility, or visual testing—or a combination.

• Language and platform: Favor tools that align with your primary language (Java, JavaScript/TypeScript, Python, .NET, Swift/Kotlin) and target platforms (web, Android, iOS).

• Ease of setup and maintainability: Prefer frameworks with built-in waits, tracing, and reporting to reduce boilerplate and flakiness.

• Execution speed and stability: Native frameworks (Espresso, EarlGrey) and modern E2E tools (Playwright) can improve stability and performance.

• CI/CD integration: Ensure seamless execution in your chosen pipeline, including parallelism, retries, and artifact collection (reports, screenshots, traces).

• Debugging and observability: Look for features like trace viewers, videos, console/network logs, and clear error messages.

• Community and ecosystem: Active communities and plugins can save time and reduce risk.

• Scalability: For large suites, consider sharding, distributed execution, and cloud/device farm strategies.

• Cost of ownership: Even open source requires investment. Consider learning curves, maintenance overhead, infrastructure needs, and flakiness management.

• Interoperability: Some tools pair well (e.g., Rest Assured with TestNG or JUnit; Selenium/Selenide with various runners). Plan your stack deliberately.

Conclusion

TestNG remains a proven and capable framework for JVM-based unit and integration testing, and it continues to anchor many Java automation stacks—especially when paired with Selenium or Selenide. However, modern QA needs often span mobile, web, APIs, performance, security, accessibility, and visual validation across multiple languages and platforms. In those scenarios, the alternatives listed here can be a better fit.

• Choose mobile-native frameworks (Espresso, EarlGrey, Appium) for stable, platform-aligned UI automation.

• Prefer modern E2E frameworks (Playwright, Playwright Test, Taiko, Puppeteer, Selenide, Selenium, Geb) for cross-browser web testing with robust tooling.

• Adopt API-focused tools (Rest Assured, Karate, Citrus) to simplify backend validation and integration testing.

• Use specialized tools (JMeter, OWASP ZAP, Lighthouse CI, Paparazzi, Shot) to cover performance, security, accessibility, and visual regressions.

• Improve test suite quality with mutation testing (PIT, Stryker).

• For language fit and readability, consider BDD/spec-driven options (Spock, Gauge, Robot Framework).

Ultimately, the best choice depends on your stack, team skills, and testing objectives. Many teams use a blended approach—keeping TestNG where it excels while introducing specialized tools to meet evolving quality and speed demands in CI/CD.