Best Free Code Coverage Tools of 2025

Sahi Pro is a suite automation tools for web, Web-services, Windows desktop and Java applications. Sahi Pro features include automatic waits, recorders and accessor spy, inbuilt frame and editor, parallel playback, automatic reporting, automatic logging, and reporting. Also, Sahi Pro can save 70% of the time and effort that is normally spent on test automation. Sahi Pro has been trusted by more than 400 companies around the world and is quickly becoming the preferred tool for test automation in the agile world.

IntelliJ IDEA by JetBrains is an IDE for professional Java and Kotlin development. It unlocks productivity and helps you write high quality code with ease. It is designed to get the job finished. It provides all the essential tools and support for cutting-edge technologies you need. It lets you code with ease and confidence thanks to a comfortable, smooth workflow and a strong emphasis on privacy and security.

Enhance your productivity by ensuring only high-quality code is released, as SonarQube Cloud (previously known as SonarCloud) seamlessly evaluates branches and enriches pull requests with insights. Identify subtle bugs to avoid unpredictable behavior that could affect users and address security vulnerabilities that threaten your application while gaining knowledge of application security through the Security Hotspots feature. Within moments, you can begin using the platform right where your code resides, benefiting from immediate access to the most current features and updates. Project dashboards provide vital information on code quality and readiness for release, keeping both teams and stakeholders in the loop. Showcase project badges to demonstrate your commitment to excellence within your communities. Code quality and security are essential across your entire technology stack, encompassing both front-end and back-end development. That’s why we support a wide range of 24 programming languages, including Python, Java, C++, and many more. The demand for transparency in coding practices is on the rise, and we invite you to be a part of this movement; it's completely free for open-source projects, making it an accessible opportunity for all developers! Plus, by participating, you contribute to a larger community dedicated to improving software quality.

Enhance the quality of your code by adopting healthier coding practices and refining your code review process. Codecov offers a suite of integrated tools designed to organize, merge, archive, and compare coverage reports seamlessly. This service is free for open-source projects, with paid plans beginning at just $10 per user each month. It supports multiple programming languages, including Ruby, Python, C++, and JavaScript, and can be effortlessly integrated into any continuous integration (CI) workflow without the need for extensive setup. The platform features automatic merging of reports across all CI systems and languages into a unified document. Users can receive tailored status updates on various coverage metrics and review reports organized by project, folder, and test type, such as unit or integration tests. Additionally, detailed comments on the coverage reports are directly included in your pull requests. Committed to safeguarding your data and systems, Codecov holds SOC 2 Type II certification, which verifies that an independent third party has evaluated and confirmed their security practices. By utilizing these tools, teams can significantly increase code quality and streamline their development processes.

DeepSource streamlines the process of identifying and resolving code issues during reviews, including risks of bugs, anti-patterns, performance bottlenecks, and security vulnerabilities. Setting it up with your Bitbucket, GitHub, or GitLab account takes under five minutes, making it incredibly convenient. It supports various programming languages such as Python, Go, Ruby, and JavaScript. Additionally, DeepSource encompasses all essential programming languages, Infrastructure-as-Code capabilities, secret detection, code coverage, and much more. This means you can rely solely on DeepSource for code protection. Initiate your development with the most advanced static analysis platform, ensuring that you catch bugs before they make their way into production. It boasts the largest array of static analysis rules available in the market. Your team will benefit from having a centralized location to monitor and address code health effectively. With DeepSource, code formatting can be automated, ensuring your CI pipeline remains intact without style violations disrupting the process. Furthermore, it can automatically generate and implement fixes for detected issues with just a few clicks, enhancing your team's productivity and efficiency.

Thanks to a comprehensive array of tools and APIs available from leading cloud providers, developing services in Go has never been more accessible. The language's extensive open-source libraries, combined with its powerful standard library, make it ideal for crafting swift and sophisticated command-line interfaces. Go's exceptional memory management and compatibility with multiple integrated development environments enhance its capability to drive rapid and scalable web applications. With quick compilation times and a clean syntax, along with built-in formatting and documentation tools, Go is tailored to meet the needs of both DevOps professionals and site reliability engineers. This is a deep dive into everything related to Go. Whether you are embarking on a fresh project or looking to refine your existing Go skills, there’s a structured interactive introduction that is divided into three parts. Each part offers practical exercises to reinforce your understanding, and the Playground feature allows users to write Go code directly in a browser, which is then compiled, linked, and executed on our servers instantly. This hands-on approach makes learning Go not only effective but also enjoyable.

PHPUnit necessitates the activation of the dom and json extensions, which are typically enabled by default, alongside the pcre, reflection, and spl extensions that are also standard and cannot be disabled without modifying PHP's build system or source code. Additionally, to generate code coverage reports, the Xdebug extension (version 2.7.0 or newer) and the tokenizer extension must be present, while the ability to create XML reports relies on the xmlwriter extension. Writing unit tests is fundamentally a best practice for developers to detect and resolve bugs, refactor code, and provide documentation for a unit of software being tested. Ideally, unit tests should encompass all potential execution paths within a program to maximize effectiveness. Generally, a single unit test is aligned with one specific path in a particular function or method. Nonetheless, it is important to recognize that a test method may not function as a completely isolated or independent unit, as there can often be subtle dependencies between various test methods that stem from the underlying implementation of a test scenario. This interconnectedness can sometimes lead to challenges in maintaining test integrity and reliability.

This module offers metrics for code coverage specifically tailored for Perl, highlighting the extent to which tests engage with the code. By utilizing Devel::Cover, users can identify sections of their code that remain untested and decide on additional tests necessary to enhance coverage. Essentially, code coverage serves as a proxy indicator of software quality. Devel::Cover has reached a commendable level of stability, incorporating an array of features typical of effective coverage tools. It provides detailed reports on statement, branch, condition, subroutine, and pod coverage. Generally, the data on statement and subroutine coverage is reliable, while branch and condition coverage may not always align with expectations. For pod coverage, it leverages Pod::Coverage, and if Pod::Coverage::CountParents is accessible, it will utilize that for more comprehensive insights. Overall, Devel::Cover stands out as an essential tool for Perl developers seeking to improve their code's robustness through better testing practices.

LuaCov serves as a straightforward coverage analysis tool for Lua scripts. By running a Lua script with the luacov module activated, it produces a statistics file detailing the execution count for each line within the script and its associated modules. This statistics file is then processed by the luacov command-line tool to create a report, enabling users to identify untraversed code paths, which is essential for assessing the thoroughness of a test suite. The tool offers a variety of configuration options, with the default settings found in src/luacov/defaults.lua, representing the global defaults. For those needing project-specific configurations, they can create a Lua script that either sets options as global variables or returns a table containing specific options, saving this file as .luacov in the project directory where luacov is executed. For instance, such a configuration could specify that only the foo module and its associated submodules should be included in the coverage analysis, indicating that these are located within the src directory. This flexibility allows developers to fine-tune their coverage analysis to better align with their project needs.

Tarpaulin serves as a tool for reporting code coverage specifically designed for the cargo build system, drawing its name from a durable cloth typically employed to protect cargo on ships. At present, it effectively provides line coverage, though it may still exhibit some minor inaccuracies in its output. Significant efforts have been made to enhance its compatibility across various projects, yet unique combinations of packages and build configurations can lead to potential issues, so users are encouraged to report any discrepancies they encounter. Additionally, the roadmap offers insights into upcoming features and improvements. On Linux systems, Tarpaulin utilizes Ptrace as its default tracing backend, which is limited to x86 and x64 architecture; however, this can be switched to llvm coverage instrumentation by specifying the engine as llvm, which is the default method on Mac and Windows platforms. Furthermore, Tarpaulin can be deployed in a Docker environment, making it a practical solution for users who prefer not to run Linux directly but still wish to utilize its capabilities locally. This versatility makes Tarpaulin a valuable tool for developers looking to improve their code quality through effective coverage analysis.

grcov is a tool that gathers and consolidates code coverage data from various source files. It is capable of processing .profraw and .gcda files produced by llvm/clang or gcc compilers. Additionally, grcov can handle lcov files for JavaScript coverage and JaCoCo files for Java applications. This versatile tool is compatible with operating systems including Linux, macOS, and Windows, making it widely accessible for developers across different platforms. Its functionality enhances the ability to analyze code quality and test coverage effectively.

Kcov is a code coverage testing tool available for FreeBSD, Linux, and OSX that caters to compiled languages, Python, and Bash. Initially derived from Bcov, Kcov has developed into a more robust tool, incorporating an extensive array of features beyond those offered by its predecessor. Similar to Bcov, Kcov leverages DWARF debugging data from compiled programs, enabling the gathering of coverage metrics without the need for specific compiler flags. This functionality streamlines the process of assessing code coverage, making it more accessible for developers across various programming languages.

A straightforward command-line utility designed to gather test coverage data from Dart VM tests, making it an essential tool for developers who require local coverage reports while working on their projects. This tool streamlines the process of analyzing test effectiveness and ensures that developers can easily monitor their code's test coverage in real-time.

Coverage offers tools for gathering, processing, and formatting coverage data specifically for Dart. The function Collect_coverage retrieves coverage information in JSON format from the Dart VM Service, while format_coverage transforms this JSON coverage data into either the LCOV format or a more readable, pretty-printed layout for easier interpretation. This set of tools enhances the ability to analyze code coverage effectively.

Primarily, the focus should be on enhancing the aesthetics of the report user interface and streamlining the Maven configuration process. Additionally, it is essential to incorporate the plugin instrumentation settings into the child projects while ensuring that the report merging settings are applied at the parent project level. This approach will create a more cohesive and user-friendly experience overall.

Cloverage defaults to using clojure.test for testing, but you can switch to midje by including the --runner :midje option. Previously, in older releases of Cloverage, it was essential to enclose midje tests within clojure.test's deftest, but that requirement has been removed in the latest versions. If you wish to utilize eftest, simply provide the --runner :eftest flag. Additionally, you have the option to customize the runner by specifying :runner-opts with a map in your project settings. It's worth noting that other testing libraries might offer their own integrations with Cloverage beyond what is provided here, so be sure to consult their documentation for more information. Overall, this flexibility allows you to tailor your testing environment to better suit your development needs.

To create test coverage reports for Xcode projects and integrate them into your continuous integration (CI) system, make sure to activate the coverage feature by checking the "Gather coverage data" option while modifying the scheme settings. This setup will help you track code quality and ensure that your tests effectively cover the necessary parts of your application, streamlining your development process.

NCover Desktop is a Windows-based tool designed to gather code coverage data for .NET applications and services. Once the coverage data is collected, users can view comprehensive charts and metrics through a browser interface that enables detailed analysis down to specific lines of source code. Additionally, users have the option to integrate a Visual Studio extension known as Bolt, which provides integrated code coverage features, showcasing unit test outcomes, execution times, branch coverage visualization, and highlighted source code directly within the Visual Studio IDE. This advancement in NCover Desktop significantly enhances the accessibility and functionality of code coverage solutions. By measuring code coverage during .NET testing, NCover offers insights into which parts of the code were executed, delivering precise metrics on unit test coverage. Monitoring these statistics over time allows developers to obtain a reliable gauge of code quality throughout the entire development process, ultimately leading to a more robust and well-tested application. By utilizing such tools, teams can ensure a higher standard of software reliability and performance.

JaCoCo, a free Java code coverage library developed by the EclEmma team, has been refined through years of experience with existing libraries. The master branch of JaCoCo is built and published automatically, ensuring that each build adheres to the principles of test-driven development and is therefore fully functional. For the most recent features and bug fixes, users can consult the change history. Additionally, the SonarQube metrics assessing the current JaCoCo implementation can be found on SonarCloud.io. It is possible to integrate JaCoCo seamlessly with various tools and utilize its features right away. Users are encouraged to enhance the implementation and contribute new functionalities. While there are multiple open-source coverage options available for Java, the development of the Eclipse plug-in EclEmma revealed that most existing tools are not well-suited for integration. A significant limitation is that many of these tools are tailored to specific environments, such as Ant tasks or command line interfaces, and lack a comprehensive API for embedding in diverse contexts. Furthermore, this lack of flexibility often hinders developers from leveraging coverage tools effectively across different platforms.

Allocate your efforts wisely between developing applications and writing corresponding test code. For Java and Groovy, utilizing an advanced code coverage tool is essential, and OpenClover stands out by evaluating code coverage while also gathering over 20 different metrics. This tool highlights the areas of your application that lack testing and integrates coverage data with metrics to identify the most vulnerable sections of your code. Additionally, its Test Optimization feature monitors the relationship between test cases and application classes, allowing OpenClover to execute only the tests pertinent to any modifications made, which greatly enhances the efficiency of test execution time. You may wonder if testing simple getters and setters or machine-generated code is truly beneficial. OpenClover excels in its adaptability, enabling users to tailor coverage measurement by excluding specific packages, files, classes, methods, and even individual statements. This flexibility allows you to concentrate your testing efforts on the most critical components of your codebase. Moreover, OpenClover not only logs the results of tests but also provides detailed coverage analysis for each individual test, ensuring that you have a thorough understanding of your testing effectiveness. Emphasizing such precision can lead to significant improvements in code quality and reliability.

The JCov open-source initiative is designed to collect quality metrics related to the development of test suites. By making JCov accessible, the project aims to enhance the verification of regression test executions within OpenJDK development. The primary goal of JCov is to ensure transparency regarding test coverage metrics. Promoting a standard coverage tool like JCov benefits OpenJDK developers by providing a code coverage solution that evolves in harmony with advancements in the Java language and VM. JCov is entirely implemented in Java and serves as a tool to assess and analyze dynamic code coverage for Java applications. It offers features that measure method, linear block, and branch coverage, while also identifying execution paths that remain uncovered. Additionally, JCov can annotate the program's source code with coverage data. From a testing standpoint, JCov is particularly valuable for identifying execution paths and understanding how different pieces of code are exercised during testing. This detailed insight helps developers enhance their testing strategies and improve overall code quality.

Simplifying JavaScript test coverage is achievable with Istanbul, which enhances your ES5 and ES2015+ code by adding line counters, allowing you to measure how thoroughly your unit tests cover your codebase. The nyc command-line interface complements various JavaScript testing frameworks like tap, mocha, and AVA with ease. By utilizing babel-plugin-Istanbul, first-class support for ES6/ES2015+ is ensured, making it compatible with the most widely used JavaScript testing tools. Additionally, nyc facilitates the instrumentation of subprocesses through its command-line capabilities. Integrating coverage into your mocha tests is a breeze; just prefix your test command with nyc. Furthermore, the instrument command from nyc can be employed to prepare source files outside the scope of your unit tests. When executing a test script, nyc conveniently displays all Node processes that are created during the run. Although nyc defaults to Istanbul's text reporter, you have the flexibility to choose an alternative reporting option that suits your needs. Overall, nyc streamlines the process of achieving comprehensive test coverage for JavaScript applications, allowing developers to ensure higher code quality with minimal effort.

Blanket.js is a user-friendly JavaScript code coverage library designed to simplify the installation, usage, and understanding of code coverage metrics. This tool allows for seamless operation or tailored customization to suit specific requirements. By providing code coverage statistics, Blanket.js enhances your current JavaScript tests by indicating which lines of your source code are being tested. It achieves this by parsing the code with Esprima and node-falafel, then adding tracking lines for analysis. The library integrates with test runners to produce coverage reports after test execution. Additionally, a Grunt plugin enables Blanket to function as a traditional code coverage tool, producing instrumented versions of files rather than applying live instrumentation. Blanket.js can also execute QUnit-based reports in a headless manner using PhantomJS, with results shown in the console. Notably, if any predefined coverage thresholds are not satisfied, the Grunt task will fail, ensuring that developers adhere to their quality standards. Overall, Blanket.js serves as an effective solution for developers seeking to maintain high test coverage in their JavaScript applications.

The jscoverage tool offers support for both Node.js and JavaScript, allowing for an expanded coverage range. To utilize it, you can load the jscoverage module using Mocha, which enables it to function effectively. When you select different reporters like list, spec, or tap in Mocha, jscoverage will append the coverage information accordingly. You can designate the reporter type using covout, which allows options such as HTML and detailed reporting. The detailed reporter specifically outputs any uncovered code directly to the console for immediate visibility. As Mocha executes test cases with the jscoverage module integrated, it ensures that any files listed in the covignore file are excluded from coverage tracking. Additionally, jscoverage generates an HTML report, providing a comprehensive view of the coverage results. By default, it looks for the covignore file in the root of your project, and it will also copy any excluded files from the source directory to the specified destination directory, ensuring a clean and organized setup for testing. This functionality enhances the testing process by clearly indicating which parts of your code are adequately covered and which areas require further attention.

SimpleCov is a Ruby tool designed for code coverage analysis, leveraging Ruby's native Coverage library to collect data, while offering a user-friendly API that simplifies the processing of results by allowing you to filter, group, merge, format, and display them effectively. Although it excels in tracking the covered Ruby code, it does not support coverage for popular templating systems like erb, slim, and haml. For most projects, obtaining a comprehensive overview of coverage results across various types of tests, including Cucumber features, is essential. SimpleCov simplifies this task by automatically caching and merging results for report generation, ensuring that your final report reflects coverage from all your test suites, thus providing a clearer picture of any areas that need improvement. It is important to ensure that SimpleCov is executed in the same process as the code for which you wish to analyze coverage, as this is crucial for accurate results. Additionally, utilizing SimpleCov can significantly enhance your development workflow by identifying untested code segments, ultimately leading to more robust applications.