OpenClover

Overview

OpenClover is a free code coverage tool for Java, Groovy and AspectJ projects. It suits teams that want detailed coverage and test-workflow tools across those languages; its Groovy IDE limitation may rule it out for some setups.

Coverage gates, historical trends and configurable metrics make it more than a basic coverage counter. The trade-off is that teams relying on Groovy support inside Eclipse or IntelliJ IDEA will need another workflow.

Compare it with other options in our Test Coverage Tools directory.

Key features

Coverage and analysis

OpenClover tracks coverage globally, per test and across distributed tests, with method, statement and branch metrics. That range helps teams investigate not only how much code tests reach, but where individual tests contribute. Historical trends provide a view of coverage changes over time, while coverage gates let teams apply criteria to coverage.

More than 20 built-in code metrics, plus support for custom metrics, broaden analysis beyond coverage. Filters can narrow scope by paths, classes, methods, code blocks, statements, complexity and inline comments. This depth is useful for focused investigations, though teams wanting only a minimal coverage summary may not need it.

Test workflows and reports

OpenClover can identify tests to rerun for modified classes, run failing tests first or randomize test order. These options connect coverage data to test execution and can help teams target reruns after code changes. Dedicated test support covers JUnit 3 and 4, TestNG and Spock.

Integrations include Ant, Maven, Gradle, Grails and Griffon, along with Jenkins, Bamboo, Eclipse, IntelliJ IDEA, Sonar and JIRA. Reports can be generated as HTML, XML, PDF, JSON or TEXT, giving teams several ways to consume or pass on results.

Pricing

OpenClover: 0.00 USD per free, billed forever. The plan has no license tiers, license keys or usage limits. OpenClover is Apache 2.0-licensed and has been free and open-source since 2017, so there is no paid tier to unlock additional capacity.

This suits teams looking for a no-cost coverage tool without per-seat or usage caps. Support is community-based through documentation, forums and the issue tracker, with typical responses within a few days; teams needing a different support arrangement should look elsewhere.

Platforms

OpenClover supports Windows, Linux and Apple Mac OS X, and is also listed for web use. Version 5.1.x supports JRE or JDK 8 through 25 and Groovy 3.x, 4.x and 5.x. Groovy is not supported in the Eclipse and IntelliJ IDEA integrations, a meaningful limitation for teams using either IDE with Groovy code.

Who it's for

OpenClover is a strong fit for Java, Groovy and AspectJ teams that want coverage at several levels, configurable metrics and reports within existing build and test workflows. Its test-selection features are especially relevant to teams that want to target reruns after modifying classes.

It is less suitable for Groovy developers who depend on Eclipse or IntelliJ IDEA integration, or for users whose language needs fall outside Java, Groovy and AspectJ.

Pros and cons

• Pros: Global, per-test and distributed per-test coverage with method, statement and branch metrics gives teams several useful ways to inspect test execution.
• Pros: Test selection, failing-test prioritization and order randomization connect coverage analysis to practical test workflows.
• Pros: The free plan has no usage limits, license tiers or license keys, and includes historical trends and coverage gates.
• Cons: Groovy is unsupported in the Eclipse and IntelliJ IDEA integrations, limiting the IDE workflow for Groovy teams.
• Cons: Support is community-based and typically responds within a few days, rather than providing an immediate support channel.

Alternatives

For Ruby projects, SimpleCov is the more relevant free, MIT-licensed coverage option. Python teams can choose free, open-source Coverage.py, which also has an enterprise subscription through Tidelift.

Coveralls is worth considering for open-source and public repositories, which it makes free. For modern .NET SDK-style projects, free, MIT-licensed Coverlet is the better language fit. Go users looking for a command-line tool can choose gofmt, an executable included with Go.

ReportGenerator offers a free open-source basic tier as well as a 10-day full-access trial, making it an option for those comparing reporting tools. Codecov has a free Developer plan with different user and repository-upload limits, so it may suit teams whose requirements fit those caps. gcovr is another free option for teams comparing coverage tools.

Verdict

Choose OpenClover if your Java, Groovy or AspectJ team wants detailed coverage analysis, configurable metrics and test-selection tools without license or usage limits. Its breadth is the main reason to choose it; Groovy's lack of support in the Eclipse and IntelliJ IDEA integrations is the clearest reason to look elsewhere.